Waves Questions

We provide waves practice exercises, instructions, and a learning material that allows learners to study outside of the classroom. We focus on waves skills mastery so, below you will get all questions that are also asking in the competition exam beside that classroom.

Waves Questions

List of waves Questions

Question NoQuestionsClass
1Assertion
When a pulse on string reflects from free end, the resultant pulse is formed
in such a way that slope of string at free end is zero.
Reason
Zero resultant slope ensures that there
is no force component perpendicular to string.
A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
C. Assertion is correct but Reason is incorrect
D. Assertion is incorrect but Reason is correct
11
2If the frequency of a transverse wave is ( 10 H z . ) And the distance between the
two consecutive wave crests is ( 2 m )
Calculate the wave speed.
11
3You have learnt that a travelling wave in one dimension is represented by a function ( y=f(x, t) ) where ( x ) and ( t ) must appear in the combination ( x-v t ) or ( x+v )
t i.e. ( y=f(x pm v t) . ) Is the converse true
? Examine if the following functions for y can possibly represent a travelling
wave:
(a) ( (x+v t)^{2} )
(b) ( log left[(boldsymbol{x}+boldsymbol{v} boldsymbol{t}) / boldsymbol{x}_{boldsymbol{o}}right] )
(c) ( 1 /(x+v t) )
11
4A particle is executing SHM of amplitude ( A, ) about the mean position ( x=0 . ) Which of the following is a
possible phase difference between the positions of the particle at ( x=+frac{A}{2} ) and ( boldsymbol{x}=-frac{boldsymbol{A}}{sqrt{mathbf{2}}} )
This question has multiple correct options
A . 75
B . ( 165^{circ} )
( mathbf{c} cdot 135^{circ} )
D. 195
11
5The density of air at NTP is
( 1.293 k g m^{-3} ) and density of mercury at
( mathbf{0}^{circ} boldsymbol{C} ) is ( mathbf{1 3 . 6} times mathbf{1 0}^{mathbf{3}} mathbf{k g m}^{-mathbf{3}} . ) If ( boldsymbol{C}_{boldsymbol{p}}= )
( 0.2417 mathrm{calkg}^{-10} mathrm{C}^{-1} ) and ( C_{v}=0.1715 )
the speed of sound in air at ( 100^{circ} mathrm{C} ) will
be ( left(boldsymbol{g}=mathbf{9 . 8} boldsymbol{N} boldsymbol{k} boldsymbol{g}^{-1}right) )
A ( .260 m s^{-1} )
B . ( 332 mathrm{ms}^{-1} )
c. ( 350.2 mathrm{ms}^{-1} )
D. ( 369.4 mathrm{ms}^{-1} )
11
6A particle executes SHM with a time
period of 16 s. ( A t ) time ( t=2 s, ) the
particle crosses the mean position
while at ( t=4 s, ) its velocity is ( 4 m s^{-1} )
The amplitude of motion in metre is?
A ( cdot sqrt{2} pi )
В. ( 16 sqrt{2} pi )
c. ( 32 sqrt{2} / pi )
D. ( 4 / pi )
11
7A metal rod ( 40 mathrm{cm} ) long is dropped on to a wooden floor and rebounds into air.
Compressional waves of many frequencies are thereby set up in the rod. If the speed of compressional waves in the rod in ( 5500 mathrm{m} / mathrm{s} ), what is the lowest frequency of compressional waves to which the rod resonated as it
rebounds?
A . 675 ( mathrm{H} )
в. 6875 Н
c. ( 16875 mathrm{Hz} )
D. о нz
11
8Match the following11
9A particle moves along the X-axis
according to the equation ( boldsymbol{x}= )
( 10 sin ^{3}(pi t) . ) the amplitudes and
frequencies of component SHMs are
A . amplitude ( 30 / 4,10 / 4 ; ) frequencies3 ( / 2,1 / 2 )
в. amplitude30/4,10/4; frequencies1/2,3/2
c. amplitude10, ( 10 ; ) frequencies1/2,1/2
D. amplitude30/4,10; frequencies3/2,
11
10If the ratio in the amplitudes for two waves of equal frequencies is 1: 3 then the ratio of the energies carried out by
the waves will be
A ( .1 ; 3 )
B. 1: 9
( c cdot 9: )
D. None of these
11
11A source of sound having frequency 2000Hr ( & ) a receiver are located at the
same point at the instant ( t=0, ) the source starts moving with const ( boldsymbol{a c c}^{n}left(boldsymbol{a}=mathbf{1 0 m} / boldsymbol{s}^{2}right) )
Find the frequency registered by the receiver at the instant ( t=10 ) sr. Velocity of sound in air is ( 340 mathrm{m} / mathrm{s} )
11
12A sound wave is a pressure wave; regions of high (compressions) and low pressure (rarefactions) are established
as the result of the vibrations of the
sound source. These compressions and
rarefactions result because sound:
A. is more dense than air and thus has more inertia causing the bunching up of sound
B. waves have a speed which is dependent only upon the properties of the medium.
C. is like all waves; it is able to bend into the regions of space behind obstacles
D. is able to reflect off fixed ends and interfere with incident wavesvibrates longitudinally; the longitudinal movement of air produces pressure fluctuations.
11
13What is the frequency in Hz from B as heard by the listener?11
14A wave of frequency 500 Hz has a phase velocity of ( 360 mathrm{m} / mathrm{s} ). The phase difference between the two displacements at a certain point in a time interval of ( 10^{-3} ) seconds will be
how much?
A ( cdot frac{pi}{2} ) radian
B. ( pi ) radian
c. ( frac{pi}{4} ) radian
D. ( frac{pi}{8} ) radian
11
15The phenomena during arising due to the superstition of waves is/are:
A. Beats
B. Stationary waves
c. Lissajous figures
D. All of these
11
16A wire of density ( rho ) is stretched between
the clamps at a distance ( L ) apart, while
being subjected to an extension ( l(l<< )
( L), Y ) is the Young's modulus of the
wire. The lowest resonant frequency of transverse vibration of the wire is
approximately given by :
A ( cdot f=frac{1}{2 L} sqrt{frac{Y L}{l rho}} )
B. ( f=frac{1}{2 L} sqrt{frac{Y rho L}{l^{2}}} )
( ^{mathrm{c}} cdot f=frac{1}{2 L} sqrt{frac{Y l}{L rho}} )
D ( f=frac{1}{2 L} sqrt{frac{L rho}{Y l}} )
11
17A long string under tension of ( 100 N )
has one end at ( x=0 . ) A sinusoidal
wave is generated at ( x=0 ) whose
equation is given by
( boldsymbol{y}= )
( (0.01 c m) sin left[left(frac{pi x}{10} mright)-50 pi t(s e c)right] )
Find the average power transmitted by
the wave.
11
18A train blowing its whistle moves with a constant velocity v away from an observer on the ground. The ratio of the
natural frequency of the whistle to that measured by the observer is found to be
1.2. If the train is at rest and the observer
moves away from it at the same velocity, this ratio would be given by
A . 0.5
B. 1.25
( c cdot 1.52 )
D. 2.05
11
19If the amplitude of waves at a distance
( 10 mathrm{cm} ) from a point source is ( A, ) the
amplitude at a distance ( 40 mathrm{cm} ) will be
A. ( A / 2 )
в. ( A / 4 )
( c . A )
D. ( 2 A )
11
20Which of the following expression is that of a simple harmonic progressive
wave?
A. ( A sin (omega t-k x) )
B. ( A sin omega t )
c. ( A sin omega t cos k x )
D. ( A cos k x )
11
21Waves inside a gas are
A. Longitudinal
B. Transverse
C . Partly longitudinal, partly transverse.
D. None of these
11
22Two open organ pipes of fundamental
frequencies ( n_{1} ) and ( n_{2} ) are joined in series. The fundamental frequency of the new pipe so obtained will be:
A ( cdot n_{1}+n_{2} )
в. ( frac{n_{1} n_{2}}{n_{1}+n_{2}} )
c. ( n_{1}+frac{n_{2}}{2} )
D. None of the above
11
23The average human ear can not distinguish the variation of intensity
A. if the variation is more than 100 times
B. if the variation is more than 16 times
c. if the variation is less than 16 times
D. if the variation is zero
11
24A car has two horns having a difference in frequency of 180 Hz. The car is approaching a stationary observer with a speed of ( 60 mathrm{ms}^{-1} ). Calculate the
difference in frequencies of the notes as heard by the observer, if velocity of sound in air is ( 330 m s^{-1} )
11
25Identify in which type of wave, particles moves parallel to the wave direction?
A. longitudinal
B. transverse
c. s waves
D. seismic
E. electromagnetic
11
26The equation of a plane progressive wave is ( boldsymbol{y}=mathbf{0 . 0 2} sin 8 boldsymbol{pi}left[boldsymbol{t}-frac{boldsymbol{x}}{mathbf{2 0}}right] . ) When it
is reflected at a rarer medium, its
amplitude becomes ( 75 % ) of its previous value. The equation of the reflected wave is
A ( cdot y=0.02 sin 8 pileft[t-frac{x}{20}right. )
B・ ( y=0.02 sin 8 pileft[t+frac{x}{20}right. )
c. ( y=0.15 sin 8 pileft[t+frac{x}{20}right. )
D. ( y=0.15 sin 8 pileft[t-frac{x}{20}right] )
11
27A source emits sound waves of
frequency ( 1000 H z . ) The source moves
to the right with a speed of ( 32 m / s ) relative to ground. On the right, a
reflecting surface moves towards left
with a speed of ( 64 m / s ) relative to
ground. The speed of sound in air is
( 332 m / s . ) Then
This question has multiple correct options
A. wavelength of reflected waves is nearly ( 0.3 mathrm{m} )
B. number of waves arriving per second which meets the reflected surface is 1320
C. speed of reflected wave is ( 268 mathrm{m} / mathrm{s} )
D. wavelength of reflected waves is nearly ( 0.2 mathrm{m} )
11
28A certain sound has a frequency of 256
hertz and a wavelength of ( 1.3 mathrm{m} ). What difference would be felt by a listener between the above sound and another
sound travelling at the same speed, but of wavelength ( 2.6 mathrm{m} ? )
11
29A string of length ( 100 mathrm{cm} ) and mass
( 0.5 g m ) is streched with a force of ( 20 N )
It is pulled at a distance of ( 12.5 mathrm{cm} ) from one end. The frequency of the note emitted by it is
A . ( 100 mathrm{Hz} )
в. ( 200 H z )
c. ( 400 H z )
D. ( 800 H z )
11
30The relation between frequency (n) and wavelength ( (lambda) ) is given by (v is velocity, n is frequency and ( T ) is time-period)
в. ( n=frac{lambda}{v} )
c. ( v=frac{n}{lambda^{2}} )
D. ( n=frac{T}{lambda} )
11
31If the particle was to start at the extreme position i.e ( x=+A ), then what will be the equation of SHM:
( mathbf{A} cdot A cos (omega t) )
B. ( operatorname{Asin}(omega t) )
c. ( operatorname{Acot}(omega t) )
D. ( operatorname{Atan}(omega t) )
11
32A string vibrates in 4 segments to a frequency of 400 Hz. What frequency will cause it to vibrate into 7 segments?
A. ( 700 H z )
в. ( 500 H z )
c. ( 400 mathrm{Hz} )
D. ( 100 H z )
11
33Consider a sinusoidal travelling wave
shown in the given figure. The wave
velocity is ( +40 c m / s . ) Find the frequency
of the wave.
A ( .20 H z )
B. ( 30 H z )
c. ( 25 H z )
D. ( 10 H z )
11
34The average power transmitted through a given point on a string supporting a sine wave is 0.40 watt when the
amplitude of wave is 2 mm. What average power will transmitted through this point its amplitudes is increased
to 4 mm?
A. 0.40 watt
B. 0.80 watt
c. 1.2 watt
D. 1.6 watt
11
35How many loops will be seen in each
string?
A. 1 in thinner wire and three ( i n ) thicker wire
B. 3 in thinner wire and 1 in thicker wire
C. 1 each
D. 3 each
11
36Which of the following quantity decrease as sound wave travels through
a medium:
A. Amplitude
B. Frequency
c. velocity
D. wavelength
11
37In a sinusoidal wave the time required
for a particular point to move from
maximum displacement is 0.17 sec then the frequency of wave is
A. ( 1.47 H z )
в. ( 0.36 mathrm{Hz} )
( mathrm{c} .2 .94 mathrm{Hz} )
D. ( 2.48 H z )
11
38A certain ( 120 mathrm{Hz} ) wave on a string has an amplitude of ( 0.160 mathrm{mm} . ) The amount of energy exists in an 80 g length of the ( operatorname{string} ) is ( 58 times 10^{-x} ) m ( J ). Find ( x )11
39In a transverse wave, the distance
between a crest and the immediate
trough is ( lambda / 2 ? )
11
40The intensities of two notes are equal. If frequency of one note is one-fourth that of the other then the ratio of their
amplitudes is
A . 16
B. 4
( c cdot 2 )
( D )
11
41Four waves are expressed as
(i) ( y_{1}=a_{1} sin omega t )
(ii) ( y_{2}=a_{2} sin 2 omega t )
(iii) ( boldsymbol{y}_{3}=boldsymbol{a}_{3} cos boldsymbol{omega} boldsymbol{t} )
(iv) ( boldsymbol{y}_{4}=boldsymbol{a}_{4} sin (boldsymbol{omega} boldsymbol{t}+boldsymbol{phi}) )
The interference is possible between
A ( cdot ) (i) and (iii)
B. (i) and (ii)
c. (ii) and (iv)
D. Not possible at all
11
42The equation of an incident wave travelling along +X direction is given by ( y=A sin (2 t-5 x) . ) This wave gets reflected at a rigid boundary. The change in phase of the wave is
A. ( pi / 2 ) radians
B. ( pi ) radians
c. ( pi / 3 ) radians
D. 2pi/3 radians
11
43If the equation of a standing wave is given by ( y=6 sin pi x cos 100 pi t, ) the
equation of the component waves are
A ( . y=3 sin (pi x+50 pi t) ) and ( 3 sin (pi x-50 pi t) )
B. ( y=3 sin (pi x+100 pi t) ) and ( 3 sin (pi x-100 pi t) )
c. ( y=6 sin (pi x+100 pi t) ) and ( 6 sin (pi x-100 pi t) )
D. ( y=6 sin (pi x+50 pi t) ) and ( 6 sin (pi x-50 pi t) )
11
44The equation of the progressive wave, where ( t ) is the time in second, ( x ) is the distance in metre is ( y=A cos 240(t- ) ( left.frac{x}{12}right) . ) The phase difference (in Sl units) between two positions0.5m apart is
A . 40
B. 20
c. 10
D. 5
11
45Three waves of amplitudes ( 12 mu m, 4 mu m )
and ( 9 mu m ) but of same frequency arrive at a point in a medium with a successive phase diffeerence of ( frac{pi}{2} ) Then the resultant amplitude is
A .4
B. 7
( c .5 )
D. 25
11
46Two particles are executing simple harmonic motion of the same
amplitude ( A ) and frequency ( omega ) along the ( boldsymbol{x}-boldsymbol{a} boldsymbol{x} boldsymbol{i} boldsymbol{s} . ) Their mean position is
separated by distance ( boldsymbol{X}_{mathbf{0}}left(boldsymbol{X}_{mathbf{0}}>boldsymbol{A}right) . ) If
the maximum separation
between them is ( left(X_{0}+Aright), ) the phase
difference between their motion is :-
A ( cdot frac{pi}{4} )
в. ( frac{pi}{6} )
c. ( frac{pi}{2} )
D. ( frac{pi}{3} )
11
47As a wave propagates,
This question has multiple correct options
A. the wave intensity remains constant for a planewave
B. the wave intensity decreases as the inverse of the distance from the source for a spherical wave
C. the wave intensity decreases as the inverse square of the distance form the source for a spherical wave
D. the wave intensity decreases as the inverse of the distance for a line source
11
48A source of frequency ( 500 H z ) emits
waves of wavelength 0.2 m. The time
the wave takes to travel a distance of
( 300 m ) is :
A. 75 seconds
B. 60 seconds
c. 12 seconds
D. 3 seconds
11
49Write a wave function describing the
wave
A. ( y=0.075 cos (1.05 x-4 pi t) )
( t )
B. ( y=0.075 cos (1.05 x-2 t) )
c. ( y=0.075 sin (1.05 x-4 pi t) )
D. None
11
50A progressive wave is given by the equation, ( boldsymbol{y}=boldsymbol{A} sin (boldsymbol{omega} boldsymbol{t}-boldsymbol{k} boldsymbol{x}) . ) The wave
velocity
A. increases with time
B. fluctuates with time
c. decreases with time
D. remains constant
11
51The equation of wave in string is ( y= ) ( 20 sin frac{pi x}{2} cos 40 pi t ) in metre. The speed
of the wave is
A. Zero
в. ( 80 mathrm{m} / mathrm{s} )
c. ( 320 m / s )
D. ( 160 mathrm{m} / mathrm{s} )
11
52Find the velocity of a wave whose
frequency is ( 60 mathrm{Hz} ) and wavelength is 20
( mathrm{m} )
11
53A magnifier lens focusses a beam of light on a sheet of paper for 5 secs and the paper starts burning. The process described here is
A. Concentrated light produces heat
B. Light energy is converted in to heat energy
c. Photons heating the paper
D. Electrons heating the paper
11
54The average power transmitted through a given point on a string supporting a
sine wave is 0.40 watt when the
amplitude of wave is 2 mm. What average power will be transmitted
through this point if its amplitude is increased to 4 mm?
11
55An excerpt from a book by Einstein and Infeld gives the following remarks concerning wave phenomena:
“A bit of gossip starting in Washington reaches New York [by word of mouth] very quickly, even though not a single individual who takes part in spreading it travels between these two cities.
There are two quite different motions involved, that of the rumor, Washington
to New York, and that of the persons who
spread the rumor.”
Identify a correct inference from the above text.
A. The particles of the medium perform motion from one place to another
B. The particles of the medium perform random motion to constitute wave motion
c. The particles constituting the medium perform only small vibrations, but the whole motion is that of a progressive wave.
D. None of these
11
56Under what conditions can path
difference and phase difference are
equal
A . ( p i )
B. ( 2 p i )
c. ( p i / 2 )
D. ( 2 p i / 3 )
11
57Which letter above represents a ( 3 lambda )
difference in path length?
A. Position A
B. Position B
c. Position ( c )
D. Position D
E. Position E
11
58Which one of the following does not
represent a travelling wave?
( mathbf{A} cdot y=f(x-v t) )
B ( cdot y=y_{max } sin k(x+v t) )
( mathbf{c} cdot y=y_{max } log (x-v t) )
D. ( y=fleft(x^{2}-v t^{2}right) )
11
59Two waves represented by ( y_{1}=a sin omega t ) and ( y_{2}=a sin (omega t+phi) ) and ( phi=frac{pi}{2} ) are
superposed at any point at a particular instant. The resultant amplitude is
( A )
B. ( 4 a )
( c cdot sqrt{2} a )
D. zero
11
60Which of the following is conserved when light waves interfere?
A. momentum
B. amplitude
c. energy
D. intensity
11
61A particle executes SHM of period 12 s. After two seconds, it passes through the centre of oscillation, the velocity is
found to be ( 3.142 mathrm{cm} s^{-1} . ) The amplitude of oscillation is:
A. ( 6 mathrm{cm} )
в. 3 ст
( mathrm{c} cdot 24 mathrm{cm} )
D. ( 12 mathrm{cm} )
11
62When a transverse plane wave traverses a medium, individual particles execute periodic motion given by the equation ( boldsymbol{y}=mathbf{0 . 2 5} cos (2 pi boldsymbol{t}-boldsymbol{pi} boldsymbol{x}) . ) The phase
difference for two positions of same particle which are occupied by time intervals 0.4 second apart is
A ( .144^{circ} )
B. ( 135^{circ} )
( mathrm{c} cdot 72^{circ} )
D. ( 108^{circ} )
11
63A person standing on a train platform listening to the whistle frequency of ( 450 H z ) of the train as it approaches her at a constant speed. As the train approaches the person on the platform, she will hear the frequency (pitch) of the whistle as:
A. Greater than ( 450 H z ) but constant
B. Less than ( 450 H z ) but constant
c. Greater than ( 450 H z ) and steadily increasing
D. Less than ( 450 H z ) and steadily increasing
E. Greater than ( 450 mathrm{Hz} ) and steadily decreasing
11
64Wavelength of wave is a distance between two particles which are
differing in phase by
( A cdot pi )
в. ( 2 pi )
c. ( frac{2 pi}{3} )
D.
11
65An earthquake generates both transverse ( (S) ) and longitudinal ( (P) ) sound waves in the earth. The speed of ( S ) waves is about ( 4.5 k m / s ) and that of ( P ) waves about ( 8.0 k m / s . A ) seismograph records ( P ) and ( S ) waves
from an earthquake. The first ( boldsymbol{P} ) wave arrives 4.0 min. before the first ( S )
wave. The epicenter of the earthquake is located at a distance of about
A ( .25 k m )
B. 250km
c. ( 2500 k m )
D. ( 5000 k m )
11
66The Sl unit of amplitude is
A. Hertz
B. Metre
c. second
D. None of these
11
67During the propagation of wave motion,
A. there is transfer of energy from one particle to another without any actual transfer of the particles of the medium.
B. there is transfer of energy from one particle to another with transfer of the particles of the medium.
C. there is no transfer of energy from one particle to another
D. None of these.
11
68Find out the frequency of orange light
whose wavelength is ( 6 times 10^{-7} ) m. The
speed of light is ( 3 times 10^{8} m / s )
A ( cdot 2 times 10^{15} mathrm{Hz} )
B . ( 2 times 10^{-15} mathrm{Hz} )
c. ( 5 times 10^{14} H z )
D. ( 5 times 10^{-14} mathrm{Hz} )
E . ( 2 times 10^{14} H z )
11
69Assertion
The decrease in speed of sound at high altitudes is due of fall in pressure at
this altitude.
Reason
The speed of sound is the same at all pressures and varies with temperature only.
A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
c. Assertion is incorrect but Reason is correct
D. Both Assertion and Reason are incorrect
11
70In a stationary wave,
A. Energy is carried away throughout the infinite medium
B. Energy is confined to a limited region of the medium.
C. Different particles in a loop have different amplitudes
D. Both (2) and (3)
11
71There are three sources of the sound of
equal intensities and frequencies 400,401 and 402 vibrations per second. The maximum number of beats/sec is:
A . 0
B. 1
( c .3 )
D.
11
72Two vibrating strings of the same material but lengths ( L ) and ( 2 L ) have
radii ( 2 r ) and ( r ) respectively. They are
stretched under the same tension.
Both the strings vibrate in their fundamental modes, the one of length ( L )
with frequency ( v_{1} ) and the other with frequency ( v_{2} . ) The ratio ( frac{v_{1}}{v_{2}} ) is given by
( A cdot 2 )
B. 4
( c .8 )
D.
11
73A bullet passes past a person at a speed ( 220 mathrm{m} / mathrm{s} ). The fractional change in the frequency of the whistling sound
heard by the person as the bullet crosses the person is (Speed of sound = ( 330 mathrm{m} / mathrm{s}) )
A. 0.67
B. 0.8
( c cdot 1.2 )
D. 3.0
11
74When a stationary wave is formed, then its frequency is
A. Same as that of the individual waves
B. Twice that of the individual waves
c. Half that of the individual waves
D. That of the individual waves
11
75When two objects vibrate at the resonance frequency, the first object increases the of the
vibrations of the second object.
A. amplitude
B. wavelength
c. frequency
D. speedd
E. period
11
76A source of wave produces 3 crest and 2 troughs in ( 2 mathrm{ms} ), the frequency of the wave is:
A . 1250 ( mathrm{Hz} )
в. 500 нz
( c .800 mathrm{Hz} )
D. 750 нz
11
77The velocity of the wave
( mathbf{A} cdot 80 mathrm{cm} / mathrm{sec} )
B. ( 112 mathrm{cm} / mathrm{sec} )
c. ( 120 mathrm{cm} / mathrm{sec} )
D. ( 140 mathrm{cm} / mathrm{sec} )
11
78The path difference between the two waves ( y_{1}=a_{1} sin left(omega t-frac{2 pi x}{lambda}right) ) and
( boldsymbol{y}_{2}=boldsymbol{a}_{2} cos left(boldsymbol{omega} boldsymbol{t}-frac{boldsymbol{2} boldsymbol{pi} boldsymbol{x}}{boldsymbol{lambda}}+boldsymbol{phi}right) )
( ^{A} cdot frac{lambda}{2 pi} )
в. ( frac{lambda}{2 pi}left(phi+frac{pi}{2}right) )
c. ( frac{lambda}{2 pi}left(phi-frac{pi}{2}right) )
( D cdot frac{2 pi}{lambda} d )
11
79The amplitude (in mm)11
80For the wave ( boldsymbol{y}=5 sin 30 pi[t- )
( (x / 240)] ) is in seconds. Find the
wavelength(in ( mathrm{cm} ) ).
11
81If a note ( x ) of unknown frequency
produces 8 beats/sec, with a source of ( 250 mathrm{Hz} ) and 12 beats/sec with a source
of ( 270 mathrm{Hz} ), the frequency of unknown source will be:
A . 258 ( mathrm{Hz} )
в. 242 на
c. 262 н
D. 282 нz
11
82the pulse in the figure shown has a speed of ( 0.1 m s^{-1} . ) the linear mass
density of the right string is 0.25 that of the left string. At what speed does the transmitted wave travel?
A ( .25 mathrm{cms}^{-1} )
B. 20cms-
( mathrm{c} cdot 15 mathrm{cms}^{-1} )
D. ( 17.5 mathrm{cms}^{-1} )
11
83A wave travelling on a string at a speed of ( 10 mathrm{m} / mathrm{s} ) causes each particle of the string to oscillate with a time period of
( 20 mathrm{ms} ). what is the wavelength of the
wave?
11
84A progressive wave is represented by ( y= ) ( 12 sin (5 t-4 x) mathrm{cm} . ) On this wave, how far
away are the two points having phase
difference of ( 90^{circ} ? )
A ( cdot frac{pi}{2} c m )
в. ( frac{pi}{4} c m )
с. ( frac{pi}{8} mathrm{cm} )
D. ( frac{pi}{16} mathrm{cm} )
11
85A single wave is called
A. a wave pulse
B. a crest
c. a trough
D. a crest and a trough
11
86A vibrating tuning fork of frequency ( v ) is
placed near the open end of a long cylindrical tube. The tube has side
opening and is also fitted with a
movable reflecting piston. As the piston
is moved through ( 8.75 c m, ) the intensity
of sound changes from a maximum to minimum. If the speed of sound is
( 350 m s^{-1}, ) then, ( v ) is
A ( .500 H z )
В. ( 1000 H z )
c. ( 2000 H z )
D. ( 4000 H z )
11
87An observer is moving with half the speed of light toward a stationary microwave source emitting waves frequency ( 10 mathrm{GHz} ). What is the frequency of the microwave measured by the observer? (speed of the light=3 ( x ) ( 10^{8} m s^{-1} )
A. ( 17.3 mathrm{GHz} )
B . 15.3 GHz
c. 10.1 Gн
D. 12.1 GHz
11
88A train is approaching towards a platform with a speed of ( 10 m s^{-1} ) while blowing a whistle of frequency ( 340 mathrm{Hz} )
What is the frequency of whistle heard by a stationary observer on the platform? Given speed of sound ( =340 m s^{-1} )
A. зЗО н 2
в. 350 нz
c. 340 н ( z )
D. 360 нz
11
89Two waves having equation ( x_{1}= )
( a sin left(omega t+phi_{1}right) ) and ( x_{2}=a sin left(omega t+phi_{2}right) )
If in the resultant wave the frequency and amplitude remains equals to amplitude of superimposing waves.
Then phase difference between them-
A ( cdot frac{pi}{6} )
в. ( frac{2 pi}{3} )
c. ( frac{pi}{4} )
D. ( frac{pi}{8} )
11
90The Doppler effect is applicable for
A . Light waves only
B. Sound waves only
c. Both light and sound waves
D. None of the above
11
91A particle executing simple harmonic motion along y-axis has its motion described by the equation ( y= ) ( boldsymbol{A} sin (boldsymbol{omega} boldsymbol{t})+boldsymbol{B} . ) The amplitude of the
simple harmonic motion is:
( A cdot A )
в. ( B )
c. ( A+B )
D. ( sqrt{A+B} )
11
92The relation between frequency ( v )
wavelength ( lambda ) and velocity of
propagation of wave ( nu ) is
A ( cdot v=frac{lambda}{nu} )
B . ( v=lambda nu )
c. ( v=frac{nu}{lambda} )
D. None of these
11
93Identify the parameter which measures
the time it takes to complete one cycle?
A . period
B. wavelength
c. frequency
D. amplitude
E. speed
11
94The ends of a stretched string of length
( L ) are fixed at ( x=0 ) and ( x=L . ) In one
experiment, the displacement of the wire is ( y_{1}=2 A sin left(frac{pi x}{L}right) sin omega t ) and
energy ( boldsymbol{E}_{1} ) and in another experiment,
its displacement is ( y_{2}= ) ( A sin left(frac{2 pi x}{L}right) sin 2 omega t ) and energy ( E_{2} )
then
( mathbf{A} cdot E_{2}=E_{1} )
B . ( E_{2}=2 E_{1} )
( mathbf{c} cdot E_{2}=4 E_{1} )
D. ( 16 E_{1} )
11
95Waves produced in the sonometer wire
are
A. transverse and progressive
B. transverse and stationary
c. longitudinal and progressive
D. longitudinal and stationary
11
96Two identical sinusoidal waves each of
amplitude ( 5 m m ) with a phase difference of ( frac{pi}{2} ) are travelling in the same direction in a string. The amplitude of the resultant wave (in ( m m ) ) is:
A. zero
B. ( 5 sqrt{2} )
c. ( frac{5}{sqrt{2}} )
D. 2.5
11
97There are three sources of sound of
equal intensities and frequencies 400,401 and 402 vibrations per
second.The number of beats/sec is
A.
B.
( c cdot 3 )
( D cdot 2 )
11
98When the two tuning forks of nearly same frequency are vibrated to produce beats, then the velocity of propagation of beats will be
A. less than that of sound
B. depend upon the relative frequency
c. more than that of sound
D. equal to that of sound
11
99Three tuning fork of frequency ( 400 mathrm{Hz} )
( 401 mathrm{Hz} ) and ( 402 mathrm{Hz} ) are sounded
simultaneously.the number of beats heard per second are :
( A cdot 1 )
B. 2
( c cdot 3 )
D. none of these
11
100If in the resultant wave the frequency and amplitude remains equals to
amplitude of superimposing waves. Then phase diff. between them is: –
Two waves having equation
[
begin{array}{l}
mathbf{x}_{1}=mathbf{a} sin left(omega mathbf{t}+mathbf{phi}_{1}right) \
mathbf{x}_{2}=mathbf{a} sin left(omega mathbf{t}+phi_{2}right)
end{array}
]
A ( cdot frac{pi}{6} )
в. ( frac{2 pi}{3} )
c. ( frac{pi}{4} )
D. ( frac{pi}{3} )
11
101In a Kundt’s tube experiment, the heaps of Iycopodium powder are collected at ( 20 mathrm{cm} ) separations. The frequency of
tuning fork used is
A ( .660 H z )
B. ( 825 mathrm{Hz} )
( mathrm{c} .775 mathrm{Hz} )
D. ( 915 ~ H z )
11
102In a medium in which a transverse
progressive wave is travelling the phase difference between two points with a distance of separation ( 1.25 mathrm{cm} ) is ( frac{pi}{4} . )
the frequency of the wave is ( 1000 H z )
its velocity will be
A ( cdot 10^{4} m / s )
в. ( 125 mathrm{m} / mathrm{s} )
c. ( 100 m / s )
D. ( 10 mathrm{m} / mathrm{s} )
11
103The pitch or frequency of the siren of the coming train appears to be increasing because of:
A. Big-bang theory
B. Doppler’s effect
c. charle’s law
D. Archemedies’ principle
11
104Standing waves are formed on a string
when interference occurs between two
waves having
A. The same amplitude travelling in the same direction with no phase difference between them
B. The same amplitude, travelling in the opposite direction with no phase difference between them
C. Different amplitudes travelling in the same direction
D. Different amplitudes travelling in the opposite direction
11
105A sound wave whose frequency is 220
( mathrm{Hz} ) has a speed of ( 440 mathrm{ms}^{-1} ) in a given
medium. Find the wavelength of the
sound.
11
106A transverse wave propagating along ( boldsymbol{x}-operatorname{axis} ) is represented by ( boldsymbol{y}(boldsymbol{x}, boldsymbol{t})= )
( 8.0 sin (0.5 pi x-4 pi t-pi / 4), ) wherex is
in metres and ( t ) is in seconds. The speed
of the wave is
A. ( 8 m / s )
в. ( 4 pi m / s )
( mathbf{c} cdot 0.5 pi m / s )
D. ( pi / 4 mathrm{m} / mathrm{s} )
11
107The persistence of sound in a closed enclosure, due to continuous reflections
at the walls, even after the source has
stopped producing sound is known as:
A. The persistence of hearing
B. An echo
c. Reverberation
D. The ultrasounds
11
108A ( 200 mathrm{Hz} ) wave with amplitude ( 1 mathrm{mm} ) travels on a long string of linear mass density 6 g/m kept under a tension of 60N. Find the average power transmitted across a given point on the string.11
109A wave train has the equation ( y= ) ( 4 sin (30 pi t+0.1 x) ) where ( x ) is in ( mathrm{cm} ) and
( t ) in seconds. What is the frequency of
the source? How much time does a
wave pulse take to reach a point ( 30 mathrm{cm} )
from it??
11
110Elastic waves in solid are:
A. Transverse Only
B. Longitudinal Only
C. Either transverse or longitudinal
D. Neither transverse nor longitudinal
11
111Two light waves are represented by ( boldsymbol{y}_{1}=mathbf{3} sin omega t ) and ( boldsymbol{y}_{2}=mathbf{4} sin left(boldsymbol{omega} boldsymbol{t}+frac{boldsymbol{pi}}{mathbf{3}}right) )
The resultant amplitude due to interference will be
A ( cdot sqrt{21} )
B. ( sqrt{26} )
c. ( sqrt{37} )
D. ( sqrt{41} )
11
112A string of length ( ^{prime} l^{prime} ) is fixed at both
ends. It is vibrating in its ( 3^{r d} ) overtone
with maximum amplitude ( ^{prime} a^{prime} . ) The amplitude at a distance ( frac{l}{3} ) from one end is:
( A )
B. 0
c. ( frac{sqrt{3} a}{2} )
D. ( frac{a}{2} )
11
113The intensity of sound after passing through a slab decreases by ( 20 % . ) On passing through two such slabs, the intensity will decrease by
A . ( 30 % )
B. ( 36 % )
c. ( 40 % )
D. ( 50 % )
11
114Disturbance produced in a material medium due to the vibratory motion of the particles of the medium is called a
A. compression
B. vibration
c. wave
D. rarefaction
11
115The equation of a wave propagating along a stretched string is given by ( boldsymbol{Y}=boldsymbol{4} sin 2 boldsymbol{pi}[(boldsymbol{t} / mathbf{0} . mathbf{0} mathbf{2})-(boldsymbol{x} / mathbf{1 0 0})] )
where ( Y ) and ( x ) are in ( mathrm{cm} ) and ( t ) in
second. Determine wavelength.
11
116A source oscillates with a frequency 25
Hz and the wave propagates with 300 ( mathrm{m} / mathrm{s} . ) Two points ( mathrm{A} ) and ( mathrm{B} ) are located at distances ( 10 mathrm{m} ) and ( 16 mathrm{m} ) away from the
source. The phase difference between ( A ) and B is
A ( cdot frac{pi}{4} )
в. ( frac{pi}{2} )
( c )
D . 2 ( pi )
11
117When a sound wave of frequency ( 300 mathrm{Hz} ) passes through medium, the maximum displacement of a particle of the
medium is ( 0.1 mathrm{cm} . ) The maximum
velocity of the particle is equal to.
( mathbf{A} cdot 60 pi mathrm{cm} / mathrm{s} )
B. ( 30 pi mathrm{cm} / mathrm{s} )
( mathrm{c} cdot 60 mathrm{cm} / mathrm{s} )
D. ( 30 mathrm{cm} / mathrm{s} )
11
118Transverse waves on a string have wave speed ( 12.0 mathrm{m} / mathrm{s}, ) amplitude ( 0.05 mathrm{m} ) and wavelength 0.4 m. The waves travel in
the ( +x ) direction and at ( t=0, ) the ( x=0 )
end of the string has zero displacement and is moving upwards. Find the transverse displacement of a point at ( x ) ( =0.25 mathrm{m} ) at time ( t=0.15 mathrm{s} )
A. ( -4.54 mathrm{cm} )
B. ( -5.54 mathrm{cm} )
c. ( -3.54 mathrm{cm} )
D. ( -9.54 mathrm{cm} )
11
119A wave is represented by the equation ( boldsymbol{y}=boldsymbol{A} sin left(mathbf{1 0} boldsymbol{pi} boldsymbol{x}+mathbf{1 5} boldsymbol{pi} boldsymbol{t}+frac{boldsymbol{pi}}{mathbf{3}}right), ) where ( boldsymbol{x} )
is in meters and ( t ) is in seconds. The
expression represents This question has multiple correct options
A. a wave travelling in the positive x-direction with a velocity ( 1.5 mathrm{m} / mathrm{s} )
B. a wave travelling in the negative x-direction with a velocity ( 1.5 mathrm{m} / mathrm{s} )
c. a wave travelling in the negative x-direction with a wavelength ( 0.2 m )
D. a wave travelling in the positive x-direction with a wavelength ( 0.2 m )
11
120The velocity of sound in air is ( 330 mathrm{m} / mathrm{s} ) The r.m.s velocity of air molecules ( (gamma= )
1.4) is approximately equal to
A. ( 400 mathrm{m} / mathrm{s} )
B. 471.4 m/s
c. ( 231 mathrm{m} / mathrm{s} )
D. ( 462 mathrm{m} / mathrm{s} )
11
121Two sinusoidal waves with same
wavelengths and amplitudes travel in opposite directions along a string with a speed ( 10 mathrm{m} s^{-1} . ) If the minimum time
interval between two instant when the
string is flat is ( 0.5 s, ) the wavelength of the waves is?
A ( .25 mathrm{m} )
в. 20
( c .15 mathrm{m} )
D. 10
11
122The equation of the progressive wave is ( boldsymbol{y}=boldsymbol{a} sin 2 pileft(boldsymbol{n} boldsymbol{t}-frac{boldsymbol{x}}{mathbf{5}}right) . ) The ratio of
maximum particle velocity to wave velocity is
A ( cdot frac{pi a}{5} )
в. ( frac{2 pi a}{5} )
c. ( frac{3 pi a}{5} )
D. ( frac{4 pi a}{5} )
11
123A metal rod of length ( 1 mathrm{m} ) is clamped at
two points as shown in the figure. Distance of the lamp from the two ends
are ( 5 c m ) and ( 15 c m ) respectively. Find the minimum and next higher
frequency of natural longitudinal oscillation of the rod. Given that Young’s modulus of elasticity and density of aluminium are ( boldsymbol{Y}=mathbf{1 . 6} times mathbf{1 0}^{mathbf{1 1}} mathbf{N m}^{-mathbf{2}} )
and ( p=2500 k g m^{-3} ) respectively.
( A cdot 40 mathrm{kHz}, 120 mathrm{kHz} )
B. 120 kHz, 40 kHz
c. ( 40 mathrm{kHz}, 40 mathrm{kHz} )
D. 1200 kHz, 120 kHz
11
124An observer moves towards a stationary
source of sound with a speed1 ( / 5^{t h} ) of speed of sound. the wavelength and
frequency of the source emitted are ( lambda )
and f respectively. The apparent frequency recorded by the observer
11
125A transverse harmonic wave on a string is described by
( boldsymbol{y}(boldsymbol{x}, boldsymbol{t})=mathbf{3} cdot mathbf{0} sin (mathbf{3 6} boldsymbol{t}+mathbf{0 . 0 1 8} boldsymbol{x}+boldsymbol{pi} / mathbf{4}) )
where ( x ) and ( y ) are in ( c m ) and ( t ) in s. The
positive direction of ( x ) is from left to
right.
(a) Is this a travelling wave or a stationary wave? If it is travelling what are the speed and direction of its propagation?
(b) What are its amplitude and
frequency?
(c) What is the initial phase at the
origin?
(d) What is the least distance between
two successive crests in the wave?
11
126In a sinusoidal wave, the time required for a particular point to move from maximum displacement to zero displacement is 0.17 sec. The frequency of the wave is :
A . ( 1.47 mathrm{Hz} )
в. 0.36 н ( z )
c. о.73 н н
D. 2.94 нz
11
127The relation between frequency (n) and wavelength ( (lambda) ) is given by (v is velocity, n is frequency and ( T ) is time-period)
в. ( n=frac{lambda}{v} )
c. ( v=frac{n}{lambda^{2}} )
D. ( n=frac{T}{lambda} )
11
128Assertion
A sinusoidal wave is created in a thick
rope by moving hand holding the rope up & down. If the hand is moved up and
down with greater frequency, the wave reached the other end more quickly.
Reason
Wave velocity is product of frequency & wavelength for a sinusoidal wave.
A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
C. Assertion is correct but Reason is incorrect
D. Assertion is incorrect but Reason is correct
11
129Assertion
Statement-1: In the case of a stationary
wave, a person hear a loud sound at the
pressure nodes as compared to the
antinodes.
and
Reason
Statement-2: In a stationary wave all
the particles of the medium vibrate in
phase.
A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-
B. Statement-1 is True, Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-
c. Statement-1 is True, Statement-2 is False
D. Statement-1 is False, Statement-2 is True.
11
130A stretched rope having linear mass density ( 5 times 10^{-2} k g m^{-1} ) is under a
tension of ( 80 N . ) The power that has to be supplied to the rope to generate harmonic waves at a frequency of ( 60 H z )
and an amplitude of ( 6 mathrm{cm} ) is
( mathbf{A} cdot 215 W )
B. ( 251 W )
( mathbf{c} .512 W )
D. ( 521 W )
11
131Two identical straight wires are stretched so as to produce 6 beats per second when vibrating simultaneously. On changing the tension slightly in one of them, the beat frequency remains
unchanged. Denoting by ( mathrm{T}_{1} ) and ( mathrm{T}_{2}, ) the higher and the lower initial tension in
the strings, then it could be said that
while making the above changes in tension:
This question has multiple correct options
( mathbf{A} cdot mathbf{T}_{2} ) was decreased
B. ( mathrm{T}_{2} ) was increased
( mathrm{c} cdot mathrm{T}_{1} ) was decreased
D. ( T_{1} ) was increased
11
132A closed organ pipe and an open pipe of
same length produce 4 beats when they are set into vibrations simultaneously. If the length of each of them were twice their initial lengths, the number of
beats produced will be
( A cdot 2 )
B. 4
( c )
( D )
11
133Calculate the wave length of the
longitudinal wave.
A. ( 1.5 mathrm{m} )
B. 3 ( m )
c. ( 4.5 mathrm{m} )
D. ( 9 mathrm{m} )
E. 18 m
11
134The equation of the progressive wave is ( boldsymbol{Y}=mathbf{3} sin left[boldsymbol{pi}left(frac{boldsymbol{t}}{mathbf{3}}-frac{boldsymbol{x}}{mathbf{5}}right)+frac{boldsymbol{pi}}{boldsymbol{4}}right] ) where ( boldsymbol{x} )
and ( Y ) are in metre and time in second.
Which of the following is correct?
A. Velocity ( V=1.5 mathrm{m} / mathrm{s} )
B. Amplitude ( A=3 mathrm{cm} )
c. Frequency ( F=0.2 mathrm{Hz} )
D. Wavelength ( lambda=10 m )
11
135A closed organ pipe and an open pipe of
same length produce 4 beats when they are set into vibrations simultaneously.
If the length of each of them were twice their initial lengths, the number of beats produced will be [Assume same mode of vibration in both cases
( A cdot 2 )
B. 4
( c )
D. 8
11
136During interference phenomenon of two
wave it is observed that maximum
amplitude to minimum amplitude ratio is ( 9: 7 . ) Find the intensity ratio of waves.
11
137A vehicle moving on a straight road sounds a whistle of frequency ( 256 mathrm{Hz} ) while nearing a hill with a velocity 10 ms ( -1 . ) The number of beats per second
observed by a person travelling in the vehicle is:
( left(V=330 m s^{-1}right) )
A. zero
B. 10
( c cdot 14 )
D. 16
11
138Transverse nature of light was confirmed by the phenomenon of the
A. refraction of light
B. diffraction of light
c. dispersion of light
D. polarization of light.
11
139Mark the correct match.
A. Good reflectors of sound – Tiles, Marble slabs.
B. Bad reflectors of sound – Thick curtains, thick carpets.
C. Good absorbers of sound – Holed cardboard.
D. All
11
140The phase difference between two
points is ( pi / 3 ) and they are 5 mm apart. The frequency of the wave is 300 Hz. The velocity of the wave is
( A cdot 5 mathrm{m} / mathrm{s} )
B. 20 ( mathrm{m} / mathrm{s} )
( c cdot 9 m / s )
D. ( 90 mathrm{m} / mathrm{s} )
11
141The ( (x, y) ) coordinates of the corners of
a square plate are ( (0,0),(L, 0),(L, L) )
and ( (0, L) . ) The edge of the plate are
clamped and transverse standing
waves are set up in it. If ( u(x, y) ) denotes
the displacement of plate at ( (x, y) ) at some instant of time, the possible expression(s) for ( u ) is (are)
( mathbf{A} cdot a cos left(frac{pi x}{2 L}right) cos left(frac{pi y}{2 L}right) )
B. ( a sin left(frac{pi x}{L}right) sin left(frac{2 pi y}{L}right) )
( ^{mathbf{c}} cdot a cos left(frac{2 pi x}{L}right) sin left(frac{pi y}{L}right) )
D. none of these
11
142When a transverse wave on a string is reflected from the free end, the phase change produced is
A. Zero rad
в. ( frac{pi}{2} ) rad
c. ( frac{3 pi}{4} ) rao
D. ( pi ) rad
11
143Two waves in a string (all in Sl units)
( operatorname{are} y_{1}=0.6 sin (10 t-20 x) ) and ( y_{2}= )
( 0.4 sin (10 t+20 x) )
Statement-1: Stationary wave can be formed by their superposition but net energy transfer through any section will
be non-zero
Statement-2: Their amplitudes are
unequal.
( A ). If both the statements are true and statement- 2 is the correct explanation of statement-
B. If both the statements are true but statement- 2 is not the correct explanation of statement- 1
c. If statement-1 is true and statement-2 is false
D. If statement- 1 is false and statement- 2 is true
11
144Particle acceleration in a travelling longitudinal wave can vary due to
A. change in properties of the medium
B. change in the angular velocity of the wave
c. change in the amplitude of the wave
D. None of these
11
145The displacement at a point due to two waves are ( y_{1}=sin (500 pi t) ) and ( y_{2}= )
( 2 sin (506 pi t) . ) The result due to their
superposition will be
11
146The wavelength of the sound between
the source and the listener in metres is
( 130 times 10^{-x} ). Find the value of ( x )
11
147A metal wire of linear mass density of
( 9.8 g m ) is stretched with a tension of
10 kg ( -w t ) betweentwo rigid supports 1
metre apart. The wire passes at its middle point between the poles of aper magnet and it vibrates in resonance when carrying an alternating current of frequency ( n ).The frequency nof the alternating source is
( mathbf{A} cdot 50 H z )
в. ( 100 H z )
c. ( 200 H z )
D. ( 25 H z )
11
148Two waves are propagating with same amplitude and nearly same frequency, they result in
A. beats
B. stationary wave
c. resonance
D. wave packet
11
149A particle starts from a point ( boldsymbol{P} ) at a
distance of ( A / 2 ) from the mean position
O & travels towards left as shown in the
figure. If the time period of ( mathrm{SHM} )
executed about ( O ) is ( T ) and amplitude ( A )
then the equation of motion of particle
is :
( mathbf{A} cdot_{x}=A sin left(frac{2 pi}{T} t+frac{pi}{6}right) )
В. ( x=A sin left(frac{2 pi}{T} t+frac{5 pi}{6}right) )
( ^{mathbf{C}} cdot_{x}=A cos left(frac{2 pi}{T} t+frac{pi}{6}right) )
D. ( x=A cos left(frac{2 pi}{T} t+frac{pi}{3}right) )
11
150A radio can tune to any station in
( 7.5 M H z ) to ( 12 M H z ) band. The
corresponding wavelength band is
A. ( 40 mathrm{m} ) to ( 25 mathrm{m} )
B. ( 30 mathrm{m} ) to ( 25 mathrm{m} )
( mathrm{c} .25 mathrm{m} ) to ( 10 mathrm{m} )
D. ( 10 mathrm{m} ) to ( 5 mathrm{m} )
11
151If we throw a stone in a pond of standing
water, the waves produced are:
A. transverse in nature
B. longitudinal in nature.
c. a combination of transverse and longitudinal in nature
D. of some other type
11
152When a vibrating tuning fork is placed on a sound box of a sonometer, 8 beats
per second are heard when the length of
the sonometer wire is kept at ( 101 mathrm{cm} ) or
( 100 mathrm{cm} . ) Then the frequency of the tuning fork is (consider that the tension in the wire is kept constant):
A ( .1616 mathrm{Hz} )
В. ( 1608 mathrm{Hz} )
( mathbf{c} cdot 1632 H z )
D. ( 1600 mathrm{Hz} )
11
153Two sound sources produce progressive
waves given by ( y_{1}=12 cos (100 pi t) ) and
( boldsymbol{y}_{2}=4 cos (102 pi t) ) near the ear of an
observer. When sounded together, the observer will hear:
A. 2 beats per second with an intensity ratio of maximun to minimum nearly 4:
B. 1 beat per second with an intensity ratio of maximumm to minimum nearly ( sqrt{2}: 1 )
c. 2 beats per second with an intensity ratio of maximun to minimum nearly 9 :
D. 1 beat per second with an intensity ratio of maximumm to minimum nearly 4:
11
154Two sound waves move in the same
direction in the same medium. The
pressure amplitude of the waves are equal but the wavelength of the first wave is double that of the second. Let
the average power transmitted across a
cross section by the two waves be ( boldsymbol{P}_{1} )
and ( P_{2} ) and their displacement
amplitudes be ( s_{1} ) and ( s_{2} ) then
( A cdot P_{1} / P_{2} )
B . ( P_{1} / P_{2}=2 )
c. ( s_{1} / s_{2}=1 / 2 )
D. ( s_{1} / s_{2}=2 / 1 )
11
155The displacement of the medium in a sound wave is given by the equation
( boldsymbol{y}_{1}=boldsymbol{A} cos (boldsymbol{a} boldsymbol{x}+boldsymbol{b} boldsymbol{t}) ) where ,a and b are
positive constants. The wave is reflected by an obstacle situated at
( x=0 . ) The intensity of the reflected
wave is 0.64 times that of the incident
wave. Then, the wavelength ond frequency of the incident wave are
A ( . a, b )
в. ( 2 pi a, 2 pi b )
c ( .2 pi / a, 2 pi / b )
D. ( 2 pi / a, b / 2 pi )
11
156A wave represented by ( boldsymbol{y}= ) ( 100 sin (a x+b t) ) is reflected from a
dense plane at the origin. If ( 36 % ) of energy is lost and rest of the energy is reflected, then the equation of the
reflected wave will be
A ( . y=-8.1 sin (a x-b t) )
B. ( y=8.1 sin (a x+b t) )
c. ( y=-80 sin (a x-b t) )
D. ( y=-10 sin (a x-b t) )
11
157A vibrator makes ( 150 mathrm{cm} ) of a string to vibrate in 6 loops in the longitudinal arrangement when it is stretched by 150
N. The entire length of the string is then weighed and is found to weigh ( 400 mathrm{mg} )
Then
This question has multiple correct options
A. Frequency of the vibrator is 3 ( mathrm{kHz} )
B. Frequency of the vibrator is ( 1.5 mathrm{kHz} )
c. Distance between two nodes is ( 25 mathrm{cm} )
D. Distance between two nodes is 33 cm
11
158( boldsymbol{x}_{1}=boldsymbol{A} sin (omega boldsymbol{t}-mathbf{0 . 1} boldsymbol{x}) ) and ( boldsymbol{x}_{2}= )
( A sin left(omega t-0.1 x-frac{phi}{2}right) . ) The resultant
amplitude of combined wave is:-
A ( cdot 2 A cos frac{phi}{4} )
B. ( A sqrt{2 cos frac{phi}{2}} )
( mathrm{c} cdot_{2 A cos frac{phi}{2}} )
D. ( A sqrt{2left(1+cos frac{phi}{4}right)} )
11
159A plane sound wave traveling with velocity ‘v’ in a medium A reaches a point on the interface of medium ( A ) and
medium B. If velocity of sound in
medium B is ( 2 v ), the angle of incidence
for total internal reflection of the wave
will be greater than ( left(sin 30^{circ}=0.5 ) and right.
( left.sin 90^{circ}=1right) )
A ( cdot 15^{circ} )
B . 30
( c cdot 45^{circ} )
D. ( 90^{circ} )
11
160A Sound wave with an amplitude of ( 3 mathrm{cm} )
starts towards right from origin and
gets reflected at a rigid wall after a
second. If the velocity of the wave is
( 340 m s^{-1} ) and it has a wavelength of ( 2 m )
the equations of incident and reflected
waves respectively could be
( mathbf{A} . quad y=3 times 10^{-2} sin pi(340 t-x) )
[
y=-3 times 10^{-2} sin pi(340 t+x) text { towards left }
]
B. ( quad y=3 times 10^{-2} sin pi(340 t+x) )
[
y=-3 times 10^{-2} sin pi(340 t+x) text { towards left }
]
c. ( y=3 times 10^{-2} sin pi(340 t-x) )
[
y=-3 times 10^{-2} sin pi(340 t-x) text { towards left }
]
D. ( y=3 times 10^{2} sin pi(340 t-x) )
[
I=3 times 10^{-2} sin pi(340 t+x) text { towards left }
]
11
161Match the answers given in list 1 with the questions in list 211
162A pulse of a wave travelling on a string towards the fixed rigid end as shown in the figure above. The pulse is:
A. Reflected and transmitted
B. Reflected and refracted
c. Reflected and reduced
D. Reflected and magnified
E. Reflected and inverted
11
163The intensity of a wave is the amount of energy incident on a surface per sec
A. True
B. False
11
164The radius of wavefront as the waves
propogate:-
A. decreases
B. increases
c. becomes zero
D. some times decreases sometimes increases
11
165Determine the power being supplied to the string.11
166When a sound wave is reflected from a
rigid wall, the phase difference between the reflected and incident wave
A. 0
в. ( pi )
c. ( pi / 2 )
D. ( pi / 4 )
11
167Calculate the wavelength of a wave if it travels with speed ( 2 mathrm{cm} / mathrm{s} ) and period is
2 s.
A. ( 0.25 mathrm{cm} )
B. ( 0.5 mathrm{cm} )
( c cdot 1 mathrm{cm} )
D. ( 2 mathrm{cm} )
E. ( 4 mathrm{cm} )
11
168In case of mechanical wave a particle oscillates and during oscillation its
kinetic energy and potential energy changes.
11
169Two strings with mass per unit length of ( 25 g / c m ) and ( 9 g / c m ) are joined together in series. The reflection coefficient for the vibration waves are
A ( cdot frac{9}{25} )
в. ( frac{3}{5} )
c. ( frac{1}{16} )
D. ( frac{9}{16} )
11
170Two waves of sound ( boldsymbol{y}_{1}= )
( mathbf{1 0} sin (mathbf{4 0 4} boldsymbol{pi} boldsymbol{t}-mathbf{0 . 2 x}) ) and ( boldsymbol{y}_{mathbf{2}}= )
( 8 sin (400 pi t-0.2 x) ) superpose. As a
result
A. at several places maximum intensity and at other places minimum intensity will be heard
B. 4 beats will be heard in a second
c. 2 beats will be heard in a second
D. there will be no change in intensity of the sound rather two separate waves would be heard
11
171Kinetic energy per unit length for a particle in a standing wave is zero at:
A. nodes
B. antinodes
c. mid-way between a node and an antinode
D. None of the above
11
172Four harmonic waves of equal
frequencies and equal intensities ( I_{0} )
have phase angles ( 0, pi / 3,2 pi / 3, ) and ( pi )
When they are superposed, the intensity
of the resulting wave is ( n I_{0} . ) The value of
n is
11
173A particle has an initial velocity of ( 3 hat{i}+ ) ( 4 hat{j} ) and an acceleration of ( 0.4 hat{i}+0.3 hat{j} . ) Its
speed after ( 10 s ) is?
11
174Waves that travel in a direction
perpendicular to direction of vibration are known as
A. Transverse waves
B. Longitudinal waves
c. sound waves
D. None of above
11
175Figure shows the shape of a part of a
long string in which transverse waves
are produced. Which pair of particles
are in phase?
( A ). A and
3. D and G
( c . ) В and ( E )
D. c and
11
176The equation of a simple harmonic
wave is given by ( boldsymbol{y}= )
( 6 sin 2 pi(2 t-0.1 x), ) where ( x ) and ( y ) are
in ( m m ) and ( t ) is in seconds. The phase
difference between two particles ( 2 m m )
apart at any instant is
A ( cdot 18^{circ} )
В. ( 36^{circ} )
( c cdot 54^{circ} )
D. ( 72^{circ} )
11
177Snapshot for a rope shown, at an instant is carrying a travelling wave towards
right, created by source vibrating with the frequency “n”. Then,
This question has multiple correct options
A. the speed of the wave is ( (4 mathrm{n}) ) (distance ab)
B. the particle at point a will be in the present phase of after ( frac{4}{3 n} ) sec.
C . the phase difference between b and e is ( frac{3 pi}{2} )
D. the wave is harmonic
11
178In a closed tube when air column is 20
( mathrm{cm} ) it is in resonance with tuning fork ( mathrm{A} ) When the length is increased by ( 2 mathrm{cm} ) then the air column is in resonance with
tuning fork B. When A and B are sounded together they produce 8 beats per second. The frequencies of the tuning forks ( A ) and ( B ) are ( (text { in } H z): )
( A cdot 40,44 )
B. 88, 80
( c cdot 80,88 )
D. 44,40
11
179The relation between velocity of sound in gas ( (v) ) and ( r . m . s ) velocity of
molecules of gas ( v_{r . m . s} ) is
A ( cdot v=v_{r, m cdot s}(gamma / 3)^{1 / 2} )
B . ( v_{r . m . s}=v(2 / 3)^{1 / 2} )
( mathbf{c} cdot v=v_{r . m . s} )
D . ( v=v_{r . m . s}(3 / gamma)^{1 / 2} )
11
180The wave length of a radio wave is ( 1.0 mathrm{m} ) Find its frequency.11
181By reference to two waves, state:
(i) the principle of superposition.
(ii) what is meant by coherence.
11
182To produce interference in sound waves This question has multiple correct options
A. sources shall emit monochromatic wavelength.
B. sources shall emit monochromatic wavelength in same phase (i.e., source be Coherent).
C. sources shall emit sound intensity irrespective of frequency.
D. sources shall be very far away
11
183A bat flies at a constant speed of ( 0.04 V )
toward a large tree trunk (where ( boldsymbol{V} )
denotes the speed of sound), the bat emits an ultrasonic pulse. The pulse is reflected off the tree and returns to the
bat, which can detect and analyse the returning signal. If the returning signal has a frequency of ( 61 k H z ), Find out the
frequency of the original ultrasonic
pulse?
( mathbf{A} .56 k H z )
в. ( 62 k H z )
( c .68 k H z )
D. ( 74 k H z )
E ( .78 k H z )
11
184Mechanical waves transport
A. Energy only
B. Energy and mass
C. Mass only
D. Neither energy not mass
11
185If wave length changes by ( Delta lambda ) then change in magnitude of propagation vector is
( A cdot Delta k )
B . ( 2 pi Delta lambda )
c. ( frac{2 pi}{lambda} Delta lambda )
D. ( frac{2 pi}{lambda^{2}} Delta lambda )
11
186The wave carries
A. Power
B. Energy
C. Displacement
D. Work
11
187A wave is propagating in positive ( x- )
direction. A time ( t=0 ) its snapshot is
taken as shown.lf the wave equation is
( boldsymbol{y}=boldsymbol{A} sin (boldsymbol{omega} boldsymbol{t}-boldsymbol{k} boldsymbol{x}+boldsymbol{phi}), ) then ( boldsymbol{phi} ) is
A. ( phi=0 )
В. ( phi=pi )
( c cdot phi=frac{pi}{2} )
D. ( phi=3 pi / 2 )
11
188The equation ( boldsymbol{y}=boldsymbol{4}+boldsymbol{2} sin (boldsymbol{6} boldsymbol{t}-boldsymbol{3} boldsymbol{x}) )
represents a wave motion with
This question has multiple correct options
A. amplitude 6 units
B. amplitude 2 units
c. wave speed 2 units
D. wave speed ( 1 / 2 ) units
11
189Which of the following waves is progressing in the ( y ) direction?
A ( . x=x_{0} cos (omega t-k y) )
в. ( y=y_{0} cos (omega t-k y) )
c. ( y=y_{0} cos k x sin omega t )
D. ( y=y_{0} sin k x cos omega t )
11
190What is the speed of the component wave?
A. ( 120 mathrm{cm} / mathrm{s} )
B. 240 cm/s
c. ( 143 mathrm{cm} / mathrm{s} )
D. ( 287 mathrm{cm} / mathrm{s} )
11
191A wave travels in a medium according to the equation of displacement given by
( boldsymbol{y}(boldsymbol{x}, boldsymbol{t})=mathbf{0 . 0 3} sin boldsymbol{pi}(boldsymbol{2} boldsymbol{t}-boldsymbol{0 . 0 1} boldsymbol{x}) )
where y and ( x ) are in meter and t in
second
The wavelength of the wave is
A. 200
B. 100 ( m )
c. ( 20 mathrm{m} )
D. ( 10 mathrm{m} )
11
192A piano wire ( 0.5 m ) long and mass ( 5 g m )
is stretched by a tension of ( 400 N ). The
number of highest overtone that can be heard by a person is
A. 160
B. 99
( c .140 )
D. 120
11
193In a fourier series, the fundamental frequency is the
A. Highest frequency sinusoid in the term
B. Lowest frequency sinusoid in the term
c. constant term
D. None of the above
11
194The equation of a wave travelling on a string is ( y=0.1 sin [1.4 x+314 t] . ) Then
In which direction does the wave travel?
Find the wave speed, the wavelength and the frequency of the wave. What is the maximum displacement
and the maximum speed of a portion of the string?
11
195A plane progressive wave has frequency ( 25 H z ) and amplitude ( 2.5 times 10^{-5} mathrm{m} ) and
initial phase zero, propagates along the negative x-direction with a velocity of ( mathbf{3 0 0 m} / )s. The phase difference
between the oscillations at two points ( 6 m ) apart along the line of propagation is :
( A )
в. ( frac{pi}{2} )
c. ( 2 pi )
D. ( frac{pi}{4} )
11
196Power of ( 10 ~ W ) is emitted by a
loudspeaker. The sound intensity
radiated by it at a distance of ( 3 m ) is
( 2 W / m^{2} . ) If the intensity of loudspeaker
is doubled the intensity at 6 m will be
( mathbf{A} cdot 1 W / m^{2} )
в. ( 4 mathrm{W} / mathrm{m}^{2} )
c. ( 0.5 W / m^{2} )
D. ( 2 mathrm{W} / mathrm{m}^{2} )
11
197In a ripple tank when one pulse is sent every tenth of a second, the distance between consecutive pulses is ( 30 m m )
In the same depth of water pulses are produced at half second intervals. What
is the new distance between
consecutive pulses?
A. ( 0.67 m m )
B. ( 6.0 m m )
( mathrm{c} .150 mathrm{mm} )
D. ( 600 mathrm{mm} )
11
198Assertion – On reflection from a rigid boundary there takes place a complete reversal of phase.
Reason – On reflection from a denser
medium, both the particle velocity and wave velocity are reversed in sign.
A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
c. Assertion is correct but Reason is incorrect
D. Both Assertion and Reason are incorrect
11
199Two identical pulses move in opposite directions with same uniform speeds on a stretched string. The width and kinetic energy of each pulse is ( L ) and ( k )
respectively. At the instant they completely overlap, the kinetic energy of
the width ( L ) of the string where they
overlap is
( A cdot k )
B. ( 2 k )
c. ( 4 k )
D. ( 8 k )
11
200Which of the following changes at an antinode in a stationary wave?
A. Density only
B. Pressure only
C. Both pressure and density
D. Niether pressure nor density
11
201The vibrations of a string of length
( 60 mathrm{cm} ) fixed at both ends are
represented by the equation ( boldsymbol{y}= ) ( 4 sin left[frac{pi x}{15}right] cos (96 pi t) ) where ( x ) and ( y ) are
in ( mathrm{cm} ) and ( t ) in sec. The equation of
component waves whose superposition gives the above wave are
A ( cdot y_{1}=2 sin left(96 pi t+frac{pi x}{5}right), y_{2}=-2 sin left(96 pi t-frac{pi x}{5}right) )
B・ ( y_{1}=2 sin left(frac{pi mathrm{x}}{5}+96 pi tright), y_{2}=-2 sin left(frac{pi mathrm{x}}{5}-96 pi tright) )
c. ( y_{1}=2 operatorname{sm}left(frac{pi mathrm{x}}{15}+96 pi tright), y_{2}=-2 sin left(96 pi t-frac{pi x}{15}right) )
D. ( y_{1}=2 sin left(frac{pi kappa}{15}+96 pi tright) y_{2}=-2 sin left(frac{pi mathrm{x}}{15}-96 pi tright) )
11
202The displacement ( y ) of a particle, if ( operatorname{given} operatorname{by} y=4 cos ^{2}left(frac{t}{2}right) sin (1000 t) )
This expression may be considered to be a result of the superposition of how many simple harmonic motions?
( mathbf{A} cdot mathbf{4} )
B. 3
( c cdot 2 )
D. 5
E. 6
11
203Two radio stations broadcast their
programmes at the same amplitude ( boldsymbol{A} )
and at slightly different frequencies ( omega_{1} )
and ( omega_{2} ) respectively where ( omega_{1}-omega_{2}= )
1 ( k H z . ) A detector receives the signals
from the two stations simultaneously. It can only detect signals of intensity ( > ) ( 2 A^{2} . ) Find the interval between
successive maxima of the intensity of the signal received by the detector.
A ( cdot 2 times 10^{-3} s )
B. ( 4 times 10^{-3} s )
c. ( 1.5 times 10^{-3} s )
D. ( 10^{-3} s )
11
204Three simple harmonic motions in the
same direction having the same amplitude ( A ) and same period are superposed. If each differs in phase
from the next by ( 45^{0}, ) then
A . the resulting amplitude is ( (1+sqrt{3}) A )
B. the resulting motion is not simple harmonic
C. The energy associated with the resulting motion ( (3+ ) ( 2 sqrt{2} ) ) times the energy associated with any single motion
D. The phase of the resultant motion relative to the first is ( 90^{circ} )
11
205Two ( S H M ) are represented by equation
( boldsymbol{x}_{1}=mathbf{4} sin left(boldsymbol{omega} boldsymbol{t}+mathbf{3 7}^{boldsymbol{o}}right) ) and ( boldsymbol{x}_{2}= )
( 5 cos (omega t) . ) The phase difference between
them is
A ( .37^{circ} )
B . ( 127^{circ} )
( c cdot 53^{circ} )
D. ( 143^{circ} )
11
206At a particular position the velocity of a particle in SHM with amplitude a is ( frac{sqrt{3}}{2} ) that at its mean position. In this position, its displacement is:
A ( cdot frac{a}{2} )
в. ( sqrt{3} frac{a}{2} frac{a}{2} )
( c cdot a sqrt{2} )
D. ( sqrt{2 a} )
11
207A wave travels on a light string. The equation of the wave is ( boldsymbol{Y}= )
( boldsymbol{A} sin left(boldsymbol{k} boldsymbol{x}-boldsymbol{omega} boldsymbol{t}+boldsymbol{3} boldsymbol{0}^{circ}right) . ) It is reflected
from a heavy string tied to an end of the
light string at ( x=0 . ) If ( 64 % ) of the
incident energy is reflected the equation of the reflected wave is
A. ( Y=0.8 A sin left(k x-omega t+30^{circ}+180^{circ}right) )
B. ( Y=0.8 A sin left(k x+omega t+30^{circ}+180^{circ}right) )
C. ( Y=0.8 A sin left(k x+omega t-30^{circ}right) )
D. ( Y=0.8 A sin left(k x+omega t+30^{circ}right) )
11
208The equation of a wave pulse is given as ( y=frac{0.8}{(4 x+5 t)+4}, ) the amplitude of the
pulse is:
A. 0.2 units
B. 0.4 units
c. 0.6 units
D. 0.8 units
11
209Choose the correct alternative(s)
regarding standing waves in a string
This question has multiple correct options
A. particles near the antinode have lesser potential energy than the particles near the node when they reaches at its extreme position
B. All the particles crosses their mean position simultaneously
C. Energy and momentum can transmitted through node
D. Particles near the antinode have lesser kinetic energy than the particles near the node when they crosses their mean position
11
210Regarding open organ pipe, which of following is correct?
A. Both ends are pressure antinodes
B. Both ends are displacement nodes
c. Both ends are pressure nodes
D. Both (1)and (2)
11
211The rate of transfer of energy in a wave
depends
A. directly on the square of the wave amplitude and square of the wave frequency
B. directly on the square of the wave amplitude and square root of the wave frequency
C. directly on the wave frequency and square of the wave amplitude
D. directly on the wave amplitude and square of the wave frequency
11
212Mark the correct statement
A. Hard surfaces are good reflectors of sound.
B. Soft surfaces are poor reflector of sound.
C. Bad reflectors of sound are good absorbers of sound.
D. All
11
213Two waves are represented by the equations ( boldsymbol{y}_{1}=boldsymbol{a} sin (boldsymbol{omega}+boldsymbol{k} boldsymbol{x}+mathbf{0 . 5 7}) boldsymbol{m} ) and
( boldsymbol{y}_{2}=boldsymbol{a} cos (boldsymbol{omega} boldsymbol{t}+boldsymbol{k} boldsymbol{x}) boldsymbol{m} )
where ( x ) is in meter and ( t ) in sec. The phase difference between them is
A. 0.57 radian
B. 1.0 radian
c. 1,25 radian
D. 1.57 radian
11
214In stationary wave the distance between two successive nodes or two successive
antinodes is equal to:
( A cdot lambda )
B. ( lambda / 2 )
c. ( lambda / 3 )
D. ( lambda / 4 )
11
215Spherical wavefronts, emanating from a
point source, Strike a plane reflecting surface. What will happen to these wave fronts, immediately after reflection?
A. They will remain spherical with the same curvature, both in magnitude and sign
B. They will become plane wave fronts
c. They will remain spherical, with the same curvature, but sign of curvature reversed
D. They will remain spherical, but with different curvature, both in magnitude and sign
11
216A uniform long rope is suspended from the roof. A transverse wave pulse is produced at its lower end. As the wave travels upward along the suspended rope, then the
1) velocity of wave increases
2) wavelength of wave increases
3) frequency of wave remains constant
A. only 1 and 2 are true
B. only 2 and 3 are true
c. only 1 and 3 are true
D. 1,2 and 3 all are true
11
217The fundamental frequency of a vibrating string fixed at both the ends is
f. Will the 5 th harmonic vibrate with the
same wavelength as that of the fundamental?
A. Yes
B. No
c. Depends on the tension in the string
D. Depends on the linear density of the string
11
218A string vibrates in its first normal mode with a frequency of 220 vibrations/s. The vibrating segment is ( 70.0 mathrm{cm} ) long and has a mass of ( 1.20 mathrm{g} ) Find the tension in the string.11
219speed of ( 340 mathrm{m} mathrm{s}^{-1} ). The wavelength of
the wave is :
( mathbf{A} cdot 1.5 times 10^{5} m )
B. 0.77 ( m )
( mathbf{c} .1 .4 mathrm{m} )
D. 1.1
11
220Which of these does not represent a
wave equation
A ( . y=operatorname{Asin}(omega t-k x) )
B. ( y=operatorname{Asin}(omega t+k x) )
c. ( y=A cos (omega t-k x) )
D. ( y=A(omega t-k x) )
11
221The equation of a progressive wave is ( boldsymbol{y}=mathbf{0 . 0 5} sin left(mathbf{2 0 0} boldsymbol{t}-frac{boldsymbol{x}}{mathbf{2}}right) ) where ( boldsymbol{x}, boldsymbol{y} ) are
in metres and ( t ) in seconds, then
a ) velocity of wave is ( 100 m s^{-1} )
b) maximum velocity of particle in the wave is ( 10 m s^{-1} )
c) wavelength of wave is ( 4 pi m )
A. only a and c are true
B. only b and c are true
c. only a and b are true
D. a,b,c are true
11
222Two identical flutes produce
fundamental notes of frequency ( 300 mathrm{Hz} )
at ( 27^{circ} mathrm{C} . ) If the temperature of the air in
one flute is increased to ( 31^{circ} mathrm{C} )
the number of beats heard per second will be :
( A )
B. 2
( c cdot 3 )
D. 4
11
223Two waves having equation ( x_{1}= )
( boldsymbol{a} sin left(omega t+mathbf{Phi}_{1}right) ) and ( boldsymbol{x}_{2}=boldsymbol{a} sin (boldsymbol{omega} boldsymbol{t}+ )
( mathbf{Phi}_{2} ) ) If in the resultant wave the
frequency and amplitude remains equals to amplitude of superimposing waves. Then phase difference between
them :
A. ( frac{pi}{6} )
в. ( frac{2 pi}{3} )
c. ( frac{pi}{4} )
D. ( frac{pi}{9} )
11
224The equation of a longitudinal wave is
represented as ( boldsymbol{y}=20 cos pi(50 t-x) )
its wavelength is
A. ( 5 m )
в. ( 2 m )
( c .50 m )
D. 20m
11
225The vibrations of a string of length ( 60 mathrm{cm} ) fixed at both ends are
represented by the equation ( y= ) ( 4 sin left(frac{pi x}{15}right) cos (96 x t) )
where ( x ) and ( y ) are in ( mathrm{cm} ) and in seconds
A. what is the maximum displacement of a point at ( x= ) ( 5 mathrm{cm}^{3} )
B. where are the nodes located along the string?
c. what is the velocity of the particle at ( x=7.5 mathrm{cm} ) at ( t= ) 0.25 sec?
D. write down the equations of the component waves whose superposition gives the above wave
11
226Ultrasonic waves produced by a
vibrating quartz crystal are:
A . only longitudinal
B. only transverse
C. both longitudinal and transverse
D. neither longitudinal nor transverse
11
227A composition string is made up by joining two strings of different masses
per unit length ( longrightarrow mu ) and ( 4 mu . ) The
composite string is under the same tension. A transverse wave pulse : ( boldsymbol{Y}= ) ( (6 m m) sin (5 t+40 x), ) where ( t^{prime} ) is in
seconds and ‘ ( x ) ‘ in meters, is sent along
the lighter string towards the joint. The joint is at ( x=0 . ) The equation of the
wave pulse reflected from the joint is
( mathbf{A} cdot(2 m m) sin (5 t-40 x) )
B. ( (4 m m) sin (40 x-5 t) )
C. ( -(2 m m) sin (5 t-40 x) )
D. ( (2 m m) sin (5 t-10 x) )
11
228If to a stationary observer the apparent frequency appear to be ( 6 / 5 ) times the actual frequency of the moving source then the speed and direction of the sound source is : (velocity of sound = ( 360 mathrm{m} / mathrm{sec}) )
A. ( 60 mathrm{m} / mathrm{s} ) towards the observer
B. 60 m/s away from the observer
c. ( 55 mathrm{m} / mathrm{s} ) towards the observer
D. 55 m/s away from the observer
11
229A progressive wave of frequency ( 500 H z ) is travelling with a speed of ( 330 m / s ) in air. The distance between the two points which have a phase
difference of ( 30^{circ} ) is:
A . ( 0.11 m )
в. 0.055 т
c. ( 0.22 m )
D. 0.025 m
11
230Figure shows a three arm tube in which
a liquid is filled upto levels of height I. It
is now rotated at an angular frequency
( omega ) about an axis passing through arm B.
The angular frequency ( omega ) at which level
of liquid in arm B becomes zero.
( mathbf{A} cdot sqrt{frac{2 g}{3 l}} )
B. ( sqrt{frac{g}{l}} )
c. ( sqrt{frac{3 g}{l}} )
D. ( sqrt{frac{3 g}{2 l}} )
11
231A star is receding away from earth with
a velocity of ( 10^{5} m / s . ) If the wavelength of its spectral line is ( 5700 A ), then Doppler shift will be
( A cdot 200 stackrel{circ}{A} )
B ( cdot 1.9 A )
c. ( 20 stackrel{circ}{A} )
D. ( 0.2 stackrel{circ}{A} )
11
232The motion of a particle is described by
( boldsymbol{x}=mathbf{3 0} sin (boldsymbol{pi} boldsymbol{t}+boldsymbol{pi} / mathbf{6}), ) where ( boldsymbol{x} ) is in ( boldsymbol{c m} )
and ( t ) in sec. Potential energy of the
particel is twice of kinetic energy for the first time after ( t=0 ) when the particle
is at position after
time.
11
233A siren placed at a railway platform is emitting sound of frequency 5 KHz. ( A )
passenger sitting in a moving train ( mathbf{A} ) records a frequency of ( 5.5 mathrm{KHz} ) while the train approaches the siren. During
his return journey in a different tran B he records a frequency of 6.0 KHz while approaching the same siren. The ratio of velocity of train ( mathrm{B} ) to that of train ( mathrm{A} ) is
A ( cdot frac{242}{252} )
B. 2
c. ( frac{5}{6} )
D. ( frac{11}{6} )
11
234The equation of the stationary wave is ( y=2 A sin left(frac{2 pi c t}{lambda}right) cos left(frac{2 pi x}{lambda}right) )
Which of the following statements is wrong?
A. The unit of ct is same as that of ( lambda )
B. The unit of ( x ). is same as that of ( lambda )
c. The unit of ct is same as that of ( x )
D. The unit of ct, lambda and ( x ) are same
11
235A sound source is moving towards stationary listener with ( frac{1}{10} ) th of the speed of sound. The ratio of apparent to real frequency is:
( ^{mathrm{A}} cdotleft(frac{9}{10}right)^{2} )
в. ( frac{10}{9} )
c. ( frac{11}{10} )
D ( cdotleft(frac{11}{10}right)^{2} )
11
236(Lambda, Hertz) is
the unit of frequency, and just means how many cycles per second. It is abbreviated as ( mathrm{Hz} )
11
237A particle is vibrating in simple harmonic motion with amplitude of ( 4 mathrm{cm} . ) At what displacement from the equilibrium position is its energy half potential and half kinetic?
A. ( 1 ~ c m )
B. ( sqrt{2} mathrm{cm} )
( c cdot 2 c m )
D. ( 2 sqrt{2} ) cm
11
238A transverse wave moves along a rope.
The diagram shows the position of the
rope at one particular time.
Which two labelled points are one
wavelength apart?
( mathbf{A} cdot W ) and ( X )
B. ( W ) and ( Z )
c. ( X ) and ( Z )
D. ( Y ) and ( Z )
11
239The vertical displacement of the particle of the string at ( x=7 mathrm{cm} ) and ( t )
( =0.01 s ) will be
A. ( 0.75 mathrm{cm} )
B. ( 0.5 mathrm{cm} )
c. ( 0.25 mathrm{cm} )
D. zero
11
240A property of the progressive wave that
does not depend upon other characteristics mentioned below is
A. wavelength
B. amplitude
c. frequency
D. wave velocity
11
241A long string under tension of ( 100 N )
has one end at ( x=0 . ) A sinusoidal
wave is generated at ( x=0 ) whose
equation is given by
( boldsymbol{y}= )
( (0.01 c m) sin left[left(frac{pi x}{10} mright)-50 pi t(s e c)right] )
Draw velocity time graph of particle at
( boldsymbol{x}=mathbf{5} boldsymbol{m} )
11
242A ( 200 H z ) wave with amplitude 1 mm
travels on a long string of linear mass of density ( 6 g m^{-1} ) kept under a tension of
( 60 N . ) The average power transmitted across a given point in the string is
A. ( 0.53 mathrm{W} )
Wh
в. ( 0.83 mathrm{W} )
c. ( 0.47 W )
D. ( 0.89 W )
11
243Assertion
The mechanical energy between consecutive node and antinode will
remain conserved in standing wave.
Reason

The mechanical energy does not flow between node and antinode in standing
wave.
A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
c. Assertion is correct but Reason is incorrect
D. Both Assertion and Reason are incorrect

11
244A pulse of a wave train travels along a stretched string and reaches the fixed end of the string. It will be reflected
back with:
A. a phase change of ( 180^{circ} ) with velocity reversed
B. the same phase as the incident pulse with no reversal of velocity
C. a phase change of ( 180^{circ} ) with no reversal of velocity
D. the same phase as the incident pulse but with velocity reversed
11
245( P ) and ( Q ) are fixed points at the end of ( a )
string. A transverse stationary wave of constant maximum amplitude is formed on the string.
( P, R ) and ( Q ) are the only points on the
string where nodes are formed. S and T are two points on the string at a distance x from R.
What is the relationship between points s and T?
A. The same amplitude and in phase
B. Different amplitudes and in phase
C. The same amplitude and a phase difference of 180
D. Different amplitudes and a phase difference of 180
11
246A small source of sound moves on a
circle as shown in fig. and an observer is
sitting at ( O . ) Let at ( v_{1}, v_{2}, v_{3} ) be the
frequencies heard when the source is at ( A, B ) and ( C ) respectively.
A ( cdot v_{1}>v_{2}>v_{3} )
в. ( v_{1}=v_{2}>v_{3} )
с. ( v_{2}>v_{3}>v_{1} )
D. ( v_{1}>v_{3}>v_{2} )
11
247An observer on the sea shore observes
54 waves reaching the coast per minute. If the wavelength is ( 10 m ), the
velocity is
A ( .9 mathrm{ms}^{-1} )
В. ( 54 m s^{-1} )
c. ( 18 mathrm{ms}^{-1} )
D. ( 36 m s^{-1} )
11
248Reflection of a light wave at a fixed point results in a phase difference between incident and reflected wave of
This question has multiple correct options
A ( cdot frac{3 pi}{2} )
в. ( 2 pi )
( c . pi )
D.
11
249Two progressive waves each of
frequency ( 10 H z ) travelling at ( 20 mathrm{cm} s^{-1} ) are superposed. In the resulting stationary wave, the distance between the successive nodes is
A ( .1 mathrm{cm} )
B. ( 2 mathrm{cm} )
c. ( 0.5 mathrm{cm} )
D. 0
11
250A source of sound produces waves of wavelength ( 20 mathrm{cm} ) in air. It is moving with a velocity one-fourth the velocity of sound towards east. The apparent wavelength noted by a man moving in the same direction with velocity equal to ( 2 / 3 mathrm{rd} ) of velocity of sound wave and at the back of source is :
A . ( 15 mathrm{cm} )
B. 50 cm
c. ( 75 mathrm{cm} )
D. 80 cm
11
251Steepness of the travelling waves is attenuated by
A. resistance of the line
B. inductance of the line
c. capacitance of the line
D. all of the above
11
252Two sounds can differ only by the difference in their loudness.
A. True
B. False
11
253A uniform string of length / is fixed at both ends such that tension T is
produced in it. The string is excited to vibrate with maximum displacement
amplitude ( a_{o} . ) The kinetic energy of the
string for its ( f ) irst overtone is given as ( frac{a_{0}^{2} pi^{2} T}{x l} . ) Find ( x )
11
254A stretched string is vibrating in the second overtone, then the number of
nodes and antinodes between the ends
of the string are respectively:
A. 4 and 3
B. 3 and 2
( c .3 ) and 4
D. 2 and 3
11
255A guitar string is ( 90 mathrm{cm} ) long and has a fundamental frequency of ( 124 H z . ) To produce a fundamental frequency of
( 186 H z, ) the guitar should be pressed at
( ? )
( mathbf{A} cdot 60 mathrm{cm} )
в. ( 30 mathrm{cm} )
( c cdot 20 c m )
D. ( 10 mathrm{cm} )
11
256Assertion
Ratio of maximum intensity and minimum intensity in interference is 25
1. Hence amplitude ratio of two waves should be 3: 2
Reason
( frac{boldsymbol{I}_{m a x}}{boldsymbol{I}_{m i n}}=left(frac{boldsymbol{A}_{1}+boldsymbol{A}_{2}}{boldsymbol{A}_{1}-boldsymbol{A}_{2}}right)^{2} )
A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
c. Assertion is correct but Reason is incorrect
D. Assertion is incorrect but Reason is correct
11
257A sound wave travels with a speed of
( 330 m s^{-1} ) in air. If the wavelength of the
wave is ( 110 c m, ) then frequency of the wave is
11
258The ( (x, y) ) co-ordinates of the corners of
a square plate are ( (mathbf{0}, mathbf{0})(boldsymbol{L}, mathbf{0})(boldsymbol{L}, boldsymbol{L}) & )
( (0, L) . ) The edges of the plate are clamped & transverse standing waves are set up in it. If ( u(x, y) ) denotes the displacement of the plate at the point ( (x, y) ) at some instant of time, the possible expression(s) for ( u ) is/are : ( (a= ) positive constant) This question has multiple correct options
A ( cdot a cos left(frac{pi x}{2 L}right) cos left(frac{pi y}{2 L}right) )
B. ( a sin left(frac{pi x}{L}right) sin left(frac{pi y}{L}right) )
( ^{mathbf{c}} cdot a sin left(frac{pi x}{L}right) sin left(frac{2 pi y}{L}right) )
D. ( a cos left(frac{2 pi x}{L}right) sin left(frac{pi y}{L}right) )
11
259A progressive wave of frequency
( mathbf{5 0 0} boldsymbol{H z} ) is travelling at a speed of
( 360 m s^{-1} . ) How far are the two points on
it having a phase difference of ( 60^{circ} )
A . ( 0.12 mathrm{m} )
B. ( 0.36 m )
c. 0.24 m
D. ( 0.18 m )
11
260The velocity of progressive wave which produces the stationary wave, ( y=2 )
( sin left(frac{pi x}{100}right) cos (pi t) mathrm{m}: )
A. ( 100 m / s )
в. ( 1 mathrm{m} / mathrm{s} )
c. ( 50 m / s )
D. ( 1000 mathrm{m} / mathrm{s} )
11
261As waves propagate through a medium,
they transport energy. We can easily
demonstrate this by
This question has multiple correct options
A. hanging an object on a stretched string and then sending a pulse down the string
B. throwing a stone into a pond
C . compressing a spring and releasing it.
D. None of these.
11
262A siren of frequency n approaches a stationary observer and then recedes from the observer. If the velocity of
source (V) < the velocity of sound(C), the apparent change in frequency is :
A. 2nv/C
B. 2nC/V
( c cdot n / V )
D. 2VC/n
11
263In the following properties of a wave, the one which is independent of the other is
A. amplitude
B. velocity
c. wavelength
D. frequency
11
264Longitudinal waves cannot travel
through
A . liquids
B. gases
c. vacuum
D. solid
11
265The equation of progressive wave is ( boldsymbol{Y}=mathbf{4} sin left{boldsymbol{pi}left(frac{boldsymbol{t}}{mathbf{5}}-frac{boldsymbol{x}}{mathbf{9}}right)+frac{boldsymbol{pi}}{mathbf{6}}right} ) where ( boldsymbol{x} )
and ( y ) are in ( mathrm{cm}, ) which of the following
statement is true?
( mathbf{A} cdot lambda=18 mathrm{cm} )
B. Amplitude = 0.04cm
c. velocity ( v=50 mathrm{cm} / mathrm{s} )
D. frequency ( f=20 mathrm{Hz} )
11
266An observer is approaching with
velocity ( v ) towards a light source. If the
velocity of light is ( c, ) then velocity of light with respect to observer will be
A . ( c-v )
B.
( mathrm{c} cdot c+v )
D. ( sqrt{1-v^{2} / c^{2}} )
11
267A transverse wave is passing through a light string shown in the figure.The
equation of wave is ( y=A sin (cos t- )
( k x) ). The area of cross-section of string
is ( A ) and density is ( p ).The hanging
mass is:
A. ( A omega )
B. ( frac{omega}{k g} )
c. ( frac{rho A omega^{2}}{k^{2} g} )
D. ( underline{k^{2}} )
11
268A string of length ( 1 mathrm{m} ) and linear mass density ( 0.01 mathrm{kg} / mathrm{m} ) is stretched to a tension of 100 N. When both ends of the
string are fixed, the three lowest
frequencies for standing wave are ( boldsymbol{n}_{1}, boldsymbol{n}_{2} ) and ( boldsymbol{n}_{3} . ) Then
A ( cdot n_{3}=5 n_{1}=f_{3}=125 mathrm{H} )
B . ( f_{3}=5 f_{1}=n_{2}=125 mathrm{Hz} )
C ( . f_{3}=n_{2}=3 f_{1}=150 mathrm{Hz} )
D. ( n_{2}=frac{f_{1}+f_{2}}{2}=75 mathrm{Hz} )
11
269A ( 40 mathrm{cm} ) long wire having a mass ( 3.2 mathrm{gm} )
and area of c.s ( 1 mathrm{mm}^{2} ) is stretched
between the support ( 40.05 mathrm{cm} ) apart. In its fundamental mode. It vibrate with a
frequency ( 1000 / 64 H z . ) Find the young’s
modulus of the wire.
A ( cdot 1 times 10^{9} mathrm{Nm}^{2} )
B . ( 2 times 10^{9} mathrm{Nm}^{2} )
c. ( 1 times 10^{8} mathrm{Nm}^{2} )
D. ( 4 times 10^{9} mathrm{Nm}^{2} )
11
270Sound waves are traveling along positive x-direction. Displacement of
particle at any time ( t ) is as shown in figure. Select the correct statement:
A. Particle located at E has its velocity in negative ( x ) direction
B. particle located at E has zero velocity
c. Both (a) and
(b) are correct
D. Both (a) and
(b) are wrong
11
271Two open pipes of length ( L ) are vibrated
simultaneously. If length of one of the
pipes is reduced by ( y, ) then the number of beats heard per second will nearly be (if the velocity of sound is ( v text { and } y<L) )
A ( cdot frac{v y}{2 L} )
B. ( frac{2 L^{2}}{V y} )
c. ( frac{v y}{2 L^{2}} )
D. ( frac{v y}{L^{2}} )
11
272The figure shows a surface ( boldsymbol{X} boldsymbol{Y} )
separating two transparent media, medium – 1 and medium – 2. The lines
( a b ) and ( c d ) represent wavefronts of ( a )
light wave travelling in medium – 1 and incident on ( X Y . ) The lines ( e f ) and ( g h )
represents wavefronts of the light wave
in medium – 2 after refraction.
Light travels as a:
A. Parallel beam in each medium
B. Convergent beam in each medium
c. Divergent beam in each mediu
D. Divergent beam in one medium and convergent beam in the other medium
11
273A particle in SHM is described by the displacement function: ( boldsymbol{x}(boldsymbol{t})= ) ( boldsymbol{A} cos (boldsymbol{omega} boldsymbol{t}+boldsymbol{phi}) cdot ) If the initial ( (mathbf{t}=mathbf{0}) )
position of the particle is ( 1 mathrm{cm} ) and its initial velocity is ( pi mathrm{cm} / mathrm{sec}, ) what is the amplitude?
A. ( sqrt{2} mathrm{cm} )
B. ( 2 c m )
c. ( sqrt{7} c m )
D. ( 12 mathrm{cm} )
11
274Interference event is observed
A. only in transverse waves
B. only in longitudinal waves
c. in both types of waves
D. none
11
275Two waves are represented by ( x_{1}= ) ( A sin left(omega t+frac{pi}{6}right) ) and ( x_{2}=A cos omega t ) then
the phase difference between them is :
A ( cdot frac{pi}{6} )
в. ( frac{pi}{2} )
( c cdot frac{pi}{3} )
D. ( pi )
11
276Select correct statement regarding waves on a string [all symbols have their usual meanings]
This question has multiple correct options
A. Power transfer through any point in standing wave is ( mu v_{p}^{2} )
B. Energy is not conserved between consecutive node and antinode.
C. Two travelling waves of same frequency which are moving in opposite direction must form standing wave
D. Speed of particle is maximum where slope is maximum
11
277A tuning fork produces 8 beats /s with a sonometer wire. When tension in the
wire is increased by ( 21 % ) again 8 beats/s produced with the same tuning fork, the frequency of the tuning fork is
( mathbf{A} cdot 168 H z )
в. ( 176 H z )
( mathrm{c} .328 mathrm{Hz} )
D. ( 336 H z )
11
278A simple wave motion represented by ( boldsymbol{y}=mathbf{5}(sin 4 boldsymbol{pi} boldsymbol{t}+sqrt{boldsymbol{3}} cos boldsymbol{4} boldsymbol{pi} boldsymbol{t}) . ) Its
amplitude is:
( A cdot 5 )
B. ( 5 sqrt{3} )
c. ( 10 sqrt{3} )
the
D. 10
11
279A travelling of frequency ( 30 mathrm{Hz} ) and velocity ( 300 mathrm{m} / mathrm{s} ) enters a water surface
and the speed of the wave becomes 400 ( mathrm{m} / mathrm{s} . ) What is the new frequency of the
wave
( A cdot 40 mathrm{Hz} )
B. 30 Нz
c. 22.5 нz
D. 10 Hz
11
280A boat at anchor is rocked by waves
whose crests are ( 100 m ) apart and
velocity is ( 25 m / s ). The boat bounces up once in every:
( mathbf{A} cdot 2500 s )
в. ( 75 s )
c. ( 4 s )
D. ( 0.25 s )
11
281There is a mistake in each of the
following ray diagrams given as Fig. 16.9
( a, b, ) and ( c . ) Make the necessary correction ( (s) )
11
282( frac{-1}{1} )11
283The stationary wave, ( boldsymbol{y}= ) ( 2 a(sin k x cos omega t), ) in a closed organ pipe
is the result of the superposition of
( boldsymbol{y}=boldsymbol{a} sin (boldsymbol{omega} boldsymbol{t}-boldsymbol{k} boldsymbol{x}) ) and:
A. ( y=-a cos (omega t+k x) )
B. ( y=a cos (omega t+k x) )
c. ( y=a sin (omega t-k x) )
D. ( y=-a sin (omega t+k x) )
11
284Equation of a stationary wave is given by
A. ( y=A sin (k x-omega t) )
B. ( mathrm{y}=2 mathrm{A} sin k x . cos omega t) )
c. ( mathrm{y}=mathrm{A} cos 2 pi(mathrm{kx}-mathrm{t} / mathrm{T}) )
D. ( y=A cos (2 pi t / I) )
11
285Let ( V_{s} ) be the speed of the source
emitting sound waves, ( n ) the actual
frequency of the source of sound, ( V ) the speed of the sound in the medium and
( n_{1} ) the frequency of sound waves as
perceived by a stationary observer to whom the source of sound is
approaching. The formula for
calculating ( n_{1} ) is :
( mathbf{A} cdot mathbf{n}_{1}=mathbf{n}left(1-mathbf{V}_{mathbf{s}} / mathbf{V}right) )
B. ( n_{1}=nleft(frac{V}{V-V_{s}}right) )
( mathbf{c} cdot mathbf{n}_{1}=mathbf{n} /left(1+mathbf{V}_{mathbf{s}} / mathbf{V}right) )
( mathbf{D} cdot mathbf{n}_{1}=mathbf{n} )
11
286Two waves of wavelengths ( 2 mathrm{m} ) and 2.02 m respectively moving with the same velocity superpose to produce 2 beats
/s. The velocity of the wave is:
A. ( 400 mathrm{m} / mathrm{s} )
B. 402 m/s
c. ( 404 mathrm{m} / mathrm{s} )
D. ( 406 mathrm{m} / mathrm{s} )
11
287Sound and light waves both:
A. have similar wavelength
B. obey the laws of reflection
C. travel as longitudinal waves
D. travel through vacuum
11
288A vibrating string of certain length ( ell ) under a tension ( T ) resonates with a
mode corresponding to the first overtone (third harmonic) of an air column of length ( 75 mathrm{cm} ) inside a tube closed at one end. The string also generates 4 beats per second when excited along with a tuning fork of frequency n. Now when the tension of the string is slightly increased the number of beats reduces 2 per second. Assuming the velocity of sound in air to be ( 340 mathrm{m} / mathrm{s}, ) the frequency nof the tuning fork in ( mathrm{Hz} ) is
( A cdot 344 )
в. ззб
( c . ) 117.
D. 109.
11
289The true statement is
A. Sound waves in air are transverse waves
B. Sound wave does not required a material medium for its propagation
C. Sound travels faster in gas than in solid
D. Sound travels faster in solid than in gas
11
290The interference phenomenon can take place
A. in transverse wave
B. in longitudinal wave
c. in electromagnetic waves
D. in all waves
11
291The displacement of a particle varies according to the relation ( boldsymbol{X}= ) ( 4(cos pi t+sin pi t) )
The amplitude of the particle is
A . -4
B. 4
c. ( 4 sqrt{2} )
D.
11
292Two waves of frequencies ( 20 mathrm{Hz} ) and 30
Hz travels out from a common point. The phase difference between them after 0.6
( sec ) is
A . ( 12 pi )
B.
( c . pi )
( D cdot frac{3 pi}{4 pi} )
11
293Q Type your question
3
second. Frequency of wave emitted by source is ( 300 H z . X X^{prime} ) is line along
common diameter of wave fonts
passing through ( ^{prime} A^{prime} . ) Distance between two consecutive wave fonts along line
( X X^{prime} ) is ( 0.9 m ) and ( 1.3 m ) in the right and
left of point ( A ) respectively. At some
instant source is at point ( boldsymbol{A} ). Detector is
placed at point ( A . ) Detector is placed at
point ( ^{prime} Q^{prime} . A Q ) makes an angle ( 60^{circ} ) with
line ( X X^{prime} . ) If frequency of wave received by detector is ( boldsymbol{f} boldsymbol{H} boldsymbol{z}, ) then ( frac{boldsymbol{f}}{mathbf{1 1 0}}(text { in } boldsymbol{H} boldsymbol{z}) )
is equal to
11
294Five beats per second are produced on vibrating two closed organ pipes simultaneously. If the ratio of their lengths is ( 21 / 20 ), then their frequencies will be
A. 105 Hz and 100 нz
B. 105 Hz and 110 нz
c. 100 Hz and 105 н ( z )
D. 110 Hz and 105 нz
11
295The speed of a wave of time period ( T )
and propagation constant ( boldsymbol{K} ) is
( ^{text {A }} cdot frac{2 pi}{T K} )
в. ( frac{T K}{2 pi} )
c. ( frac{1}{T K} )
D. ( frac{T}{K} )
11
296In a stationary wave:
A. Strain is maximum at antinodes
B. Strain is minimum at nodes
C. Strain is maximum at nodes
D. Amplitude is zero at all points
11
297A glass tube of ( 2 mathrm{m} ) length is filled with
water. The water can be drained out
slowly at the bottom of the tube. If a vibrating tuning fork of frequency 500 ( mathrm{Hz} ) is brought at the upper end of the tube and the velocity of sound is 300 ( mathrm{m} / mathrm{s}, ) then the total number of
resonances obtained will be
( A cdot 6 )
B. 7
( c cdot 2 )
D.
11
298A broadcasting station transmits waves
of frequency ( 71 times 10^{4} H z ) with speed of
( 3 times 10^{8} m / s . ) The wavelength of the
wave is :
A . ( 418.8 mathrm{m} )
B. 324.6 m
c. ( 208.4 mathrm{m} )
D. 422.5 m
11
299The tension, length, diameter and density of a string ( mathrm{B} ) are double than that of another string A. Which of the following overtones of B is same as the fundamental frequency of A?
A . ( 1 s )
B. 2nd
( c .3 r d )
D. 4 th
11
300If at ( t=0, ) a travelling wave pulse on a string is described by the function. ( y=frac{6}{x^{2}+3} . ) What will be the wave
function representing the pulse at
time ( t, ) if the pulse is propagating along positive ( x ) -axis with speed ( 4 mathrm{m} / mathrm{s} ? )
A ( cdot y=frac{6}{(x+4 t)^{2}+3} )
B. ( y=frac{6}{(x-4 t)^{2}+3} )
c. ( y=frac{6}{(x-t)^{2}} )
D. ( y=frac{6}{(x-t)^{2}+12} )
11
301A long string having a cross-sectional
area ( 0.80 m m^{2} ) mm2and density,
( 12.5 g / c c ) is subjected to a tension of
( 64 N ) along the positive ( x ) -axis. One end of this string is attached to a vibrator at ( x=0 ) moving in transverse direction at
a frequency of ( 20 H z . A t t=0, ) the source is at a maximum displacement
( boldsymbol{y}=1.0 mathrm{cm} . ) What is the displacement of
the particle of the string at ( x=50 c m ) at
time ( t=0.05 s ? )
A ( .0 .71 mathrm{cm} )
B. ( 0.91 mathrm{cm} )
c. ( 0.58 mathrm{cm} )
D. ( 0.31 mathrm{cm} )
11
302Which one of the following material will reflect sound better?
A. Thermocole
B. Curtain made from cloth
c. steel
D. Paper
11
303The speed of sound in hydrogen at ( N T P )
is ( 1270 m s^{-1} . ) Then the speed in a
mixture of hydrogen and oxygen in the ratio 4: 1 by volume will be
( mathbf{A} cdot 317 m s^{-1} )
B . ( 635 mathrm{ms}^{-1} )
c. ( 830 m s^{-1} )
D. ( 950 mathrm{ms}^{-1} )
11
304The distance between 50 consecutive
crests is ( 10 mathrm{cms} ). Find the wavenumber
A. ( 50 / mathrm{m} )
B. 500 / m
c. ( 250 / mathrm{m} )
D. 25/ ( m )
11
305Two person ( A ) and ( B ), each carrying a source of frequency ( 300 mathrm{Hz} ), are standing a few metre apart. A starts moving towards B with velocity ( 30 mathrm{m} / mathrm{s} ) If the speed of sound is ( 300 mathrm{m} / mathrm{s} ), which of the following is true?
A. number of beats by A is higher than that heard by E
B. the number of beats by B are 30 Hz
c. both (a) and (b) are correct
D. both (a) and (b) are wrong
11
306Water waves are both longitudinal and
transverse. State whether true or false
A. True
B. False
11
307The formula proposed by Newton for velocity of sound in air is based on
process.
11
308The waves propagating on water
surface are

This question has multiple correct options
A. ultrasonic
B. Iongitudinal
c. unaudible
D. transverse

11
309In the equation of the motion of a particle ( boldsymbol{y}=mathbf{0 . 5} sin (mathbf{0 . 3} boldsymbol{t}+mathbf{0 . 1}), ) the
initial phase of motion is
A. ( (0.3 t+0.1) )
B. 0.3
c. ( 0.3 t )
D. ( 0 . )
11
310( A, B ) and ( C ) are three tuning forks. Frequency of ( A ) is 350 Hz. Beats produced by A and B are 5/s and by B and ( C ) are ( 4 / ) s. When a wax is put on ( A )
beat frequency between ( A ) and ( B ) is ( 2 mathrm{Hz} ) and between ( A ) and ( C ) is 6 Hz. Then
frequency of ( mathrm{B} ) and ( mathrm{C} ) respectively are
( A cdot 355 ) НZ, 349 Нz
B. 345 Нz, 341 Нz
c. 355 Нz, 341 Нz
D. 345 Hz, 349 Нz
11
311The shape of the string is drawn at ( t=0 ) and the area of the pulse enclosed by the string and the ( x ) -axis ismeasured. it
will be equal to
( A cdot 2 c m^{2} )
B. ( 2.5 mathrm{cm}^{2} )
c. ( 4 c m^{2} )
( D cdot 5 c m^{2} )
11
312A wave represented by the equation ( boldsymbol{Y}=boldsymbol{A} cos (boldsymbol{k} boldsymbol{x}-boldsymbol{omega} boldsymbol{t}) ) is superimposed
with another wave to form a stations
wave such that the point ( x=0 ) is a node. The equation of the other wave is
A ( .-A sin (k x+omega t) )
B. ( -A cos (k x+omega t) )
c. ( A sin (k x+omega t) )
D. ( A cos (k x+omega t) )
11
313A string of mass ( 3 mathrm{kg} ) is under tension of 400N. The length of the stretched string
is ( 25 mathrm{cm} . ) If the transverse jerk is stuck
at one end of the string find the
velocity?
A ( cdot 25 pi^{2} m s^{-2} )
B. ( -5 pi^{2} m s^{-2} )
( mathbf{c} cdot 5 pi^{2} m s^{-2} )
D. ( -25 pi^{2} m s^{-2} )
11
314Three one dimensional mechanical
waves in an elastic medium is given as
and
( boldsymbol{y}_{1}=mathbf{3} boldsymbol{A} sin (boldsymbol{omega} boldsymbol{t}-boldsymbol{k} boldsymbol{x}) )
( boldsymbol{y}_{2}=boldsymbol{A} sin (boldsymbol{omega} boldsymbol{t}-boldsymbol{k} boldsymbol{x}+boldsymbol{pi}) )
( boldsymbol{y}_{3}=2 boldsymbol{A} sin (boldsymbol{omega} boldsymbol{t}+boldsymbol{k} boldsymbol{x}) )
are superimposed with each other. The
maximum displacement amplitude of the medium particle would be
( A cdot 4 A )
B. 3A
c. ( 2 A )
D. A
11
315Find the speed of sound in a mixture of
mole of ( H e ) and 2 mole of ( O_{2} ) at ( 27^{circ} C )
A ( cdot 480 m s^{-1} )
B. ( 621 m s^{-1} )
c. ( 401 mathrm{ms}^{-1} )
D. ( 601 m s^{-1} )
11
316In stationary waves, nodes are the
points where there is:
A. maximum displacement and minimum pressure change
B. minimum displacement and maximum pressure change
C. minimum displacement and minimum pressure change
D. maximum displacement and maximum pressure change
11
317When a transverse plane wave traverses a medium, individual particles execute periodic motion given by the equation ( boldsymbol{y}=mathbf{0 . 2 5} cos (mathbf{2} boldsymbol{pi} boldsymbol{t}-boldsymbol{pi} boldsymbol{x}) . ) The phase
difference for two position of same particle which are occupied by time intervals 0.4 second apart is
11
318The distance between two consecutive
crests in a wave train produced in string is ( 5 mathrm{m} ). If two complete waves pass through any point per second, the velocity of wave is:
A ( .2 .5 mathrm{m} / mathrm{s} )
B. ( 5 mathrm{m} / mathrm{s} )
c. ( 10 mathrm{m} / mathrm{s} )
D. ( 15 mathrm{m} / mathrm{s} )
11
319Waves on water surface are
A. Longitudinal
B. Transverse
C. Combination of longitudinal and transverse
D. None of these
11
320What is the minimum distance
between two crests called?
A. Wavelength
B. Amplitude
c. Displacement
D. wave pulse
11
321A sonometer wire, ( 100 mathrm{cm} ) in length has a fundamental frequency of 330 Hz. The velocity of propagation of transverse waves along this wire is :
A ( .330 mathrm{ms}^{-1} )
B. ( 660 mathrm{ms}^{-1} )
C. ( 115 mathrm{ms}^{-1} )
D. ( 990 mathrm{ms}^{-1} )
11
322approaching the first? (answer in Hz)11
323Two identical travelling waves, moving in the same direction, are out of phase by ( pi / 2 ) rad. What is the amplitude of
the resultant wave in terms of the
common amplitude ( y_{m} ) of the two
waves.
11
324Two cars ( A ) and ( B ) approach stationary observer from opposite sides as shown in fig. Observer hears no beats. If the frequency of the horn of the ( operatorname{car} B ) is ( 504 H z, ) the frequency
of horn of car ( A ) will be :
A ( .529 .2 mathrm{Hz} )
в. ( 295.2 mathrm{Hz} )
с. ( 440.5 mathrm{H} )
D. none of these
11
325A rod ( 70 mathrm{cm} ) long is clamped from middle. The velocity of sound in the
material of the rod is 3500 ms( ^{-1} ). The
frequency of fundamental note
produced by it is :
A. ( 3500 mathrm{Hz} )
B . ( 2500 H z )
c. ( 1250 H z )
D. ( 700 mathrm{Hz} )
11
326A piece of cork is floating on water in a
small tank. The cork oscillates up and
down vertically when small ripples pass
over the surface of water. The velocity of
the ripples being ( 0.21 m s^{-1}, ) wave
length ( 15 mathrm{mm} ) and amplitude ( 5 mathrm{mm} ), the
maximum velocity of the piece of cork is ( left(boldsymbol{pi}=frac{mathbf{2 2}}{mathbf{7}}right) )
A. ( 0.44 mathrm{ms}^{-1} )
B. ( 0.24 mathrm{ms}^{-1} )
c. ( 2.4 mathrm{ms}^{-1} )
D. ( 4.4 mathrm{ms}^{-1} )
11
327A wire is stretched and fixed at two
ends. Transverse stationary waves are formed in it. It oscillates in its third
overtone mode. The equation of stationary wave is ( Y=A sin k x cos omega t )
Choose the correct options.
This question has multiple correct options
A ( cdot ) Amplitude of constituent waves is ( frac{A}{2} )
B. The wire oscillates in three loops
C ‘ the length of wire is ( frac{4 pi}{k} )
D. speed of stationary wave is ( frac{omega}{k} )
11
3286. While measuring the speed of sound by performing a
resonance column experiment, a student gets the first
resonance condition at a column length of 18 cm during
winter. Repeating the same experiment during summer,
she measures the column length to be x centimetre for the
second resonance. Then
(a) 54 >x> 36
(b) 36 > x > 18
(c) 18 > x
(d) x > 54 (AIEEE 2008)
11
329Equations of a stationary wave and a travelling wave are ( boldsymbol{y}_{1}= )
( mathbf{1} sin (boldsymbol{k} boldsymbol{x}) cos (boldsymbol{omega} boldsymbol{t}) ) and ( boldsymbol{y}_{2}=boldsymbol{a} sin (boldsymbol{omega} boldsymbol{t}- )
( k x ). The phase difference between two
points ( x_{1}=frac{pi}{3 k} ) and ( x_{2}=frac{3 pi}{2 k} ) is ( phi_{1} ) for
the first wave and ( phi_{2} ) for the second wave.The ratio ( frac{phi_{1}}{phi_{2}} ) is
A.
B. 5/6
( c cdot 3 / 4 )
D. 6/7
11
330The minimum distance between two
particles in same phase is ( 18 mathrm{cm} ). If the
velocity of the wave is ( 36 m s^{-1}, ) then find the time interval after which the
given particle undergoes a phase change of ( pi )
11
331A particle executes SHM with time period ( boldsymbol{T} ) and amplitude ( boldsymbol{A} ). The
maximum possible average velocity in time ( boldsymbol{T} / boldsymbol{4} ) is:
( ^{mathrm{A}} cdot frac{2 A}{T} )
в. ( frac{4 A}{T} )
c. ( frac{8 A}{T} )
D. ( frac{4 sqrt{2} A}{T} )
11
332The necessary condition for an
interference by two sources of light is
that:
A. two light sources must have the same wavelength
B. two point sources should have the same amplitude and same wavelength
C. two sources should have the same wavelength, nearly the same amplitude and have a constant phase angle difference
D. the two point sources should have a randomly varying phase difference
11
333Transverse waves are produced in a long string by attaching its free end to a vibrating tuning fork. Figure shows the shape of a part of the string. The points in phase are
A. A and
B. B and E
( c cdot c ) and ( F )
D. A and G
11
334If the distance between two successive
crests of a wave is ( 14 mathrm{cm}, ) the distance between two successive troughs is 7
( mathrm{cm} )
A. True
B. False
11
335The speed of a longitudinal wave in a mixture of hellium and neon at ( 300 mathrm{k} )
was found to be ( 758 mathrm{m} / mathrm{s} ). The
composition of the mixture would then
be
( mathbf{A} cdot 13: 3 )
B . 4: 3
c. 2: 1
D. 4: 1
11
336The product of the time period of a wave and its frequency is
A . Infinite
B. Zero
c. More than unity but less than infinity
D. Unity
11
337When a source moves away from stationary observer with velocity v then
apparent change in frequency is ( Delta n_{1} )
When an observer approaches the stationary source with same velocity
then change in frequency is ( Delta n_{2} ) then :
A ( cdot Delta n_{1}=Delta n_{2} )
в. ( Delta n_{1}>Delta n_{2} )
c. ( Delta n_{1}<Delta n_{2} )
D. ( Delta n_{1}=2 Delta n_{2} )
11
338Amplitude of a wave is represented by ( A=frac{c}{a+b-c} . ) Then resonance will
occur when
A. ( b=-c / 2 )
B. ( b=0 ) and ( a=c )
c. ( b=-a / 2 )
D. None of the above
11
339When a wave travels in a medium, is transferred from one
place to other with the wave.
A . mass
B. velocity
c. density
D. energy
11
340In a ripple tank,15 full ripples are produced in one second. if the distance between a trough and the next crest is 20 c.Calculate frequency
A . 2 н ( z )
B. 12 Hz
( c cdot 15 mathrm{Hz} )
D. 22 Hz
11
341sinusoidal waves ( 5.00 mathrm{cm} ) in amplitude are to be transmitted along a string having a linear mass density equal to
( 4.00 times 10^{-2} k g / m . ) If the source can
deliver an average power of ( 90 W ) and the string is under a tension of ( 100 N )
then find the frequency at which the source can operate. (take ( left.pi^{2}=10right) )
11
342Find the time period of a wave whose frequency is ( 400 mathrm{Hz} ? )
A. 0.0012 s
B. 0.0025 s
c. 0.0015 s
D. 0.0010 s
11
343Two sinusoidal waves of the same
frequency travel in the same direction
along a string. If ( boldsymbol{A}_{mathbf{1}}=mathbf{3 . 0} boldsymbol{c m}, boldsymbol{A}_{mathbf{2}}= )
( 4.0 mathrm{cm}, phi_{1}=0, ) and ( phi_{2}=pi / 2 mathrm{rad}, ) what
is the amplitude of the resultant wave?
A. ( 5 mathrm{cm} )
B. ( 6 mathrm{cm} )
( c cdot 7 mathrm{cm} )
D. ( 8 mathrm{cm} )
11
344According to Newton’s formula, the speed of sound in air at STP is:
(Take the mass of 1 mole of are is ( 29 times )
( left.10^{-3} k gright) )
( mathbf{A} cdot 250 m s^{-1} )
B . ( 260 mathrm{m} mathrm{s}^{-1} )
c. ( 270 m s^{-1} )
D. ( 280 mathrm{m} mathrm{s}^{-1} )
11
345If a source emitting waves of frequency
( f ) moves towards an observer with a
velocity ( frac{v}{4} ) and the observer moves away
from the source with a velocity ( boldsymbol{v} / boldsymbol{6}, ) the
apparent frequency as heard by the observer will be ( (v= ) velocity of sound)
A ( cdot frac{14}{15} )
B. ( frac{14}{9} )
c. ( frac{10}{9} )
D. ( frac{2}{3} f )
11
346In a ripple tank,15 full ripples are produced in one second. if the distance between a trough and the next crest is 20 c.Calculate frequency
A . 2 н ( z )
B. 12 Hz
( c cdot 15 mathrm{Hz} )
D. 22 Hz
11
347Two waves of amplitudes ( A_{0} ) and ( x A_{0} )
pass through a region.If ( x>1, ) what is the difference in the maximum and
minimum resultant amplitude is :
A ( cdot(x+1) A_{0} )
в. ( (x-1) A_{0} )
c. ( 2 x A_{0} )
D. ( 2 A_{0} )
11
348Find the size of object which can be featured with ( 5 M H z ) in water.
A. ( 0.148 mathrm{mm} )
B. ( 0.3 mathrm{mm} )
( c .0 .5 mathrm{mm} )
D. ( 0.1 mathrm{mm} )
11
349A plane wave ( boldsymbol{y}=boldsymbol{a} sin (boldsymbol{omega} boldsymbol{t}-boldsymbol{k} boldsymbol{x}) )
propagates through a stretched string. The particle velocity versus ( x ) graph at ( boldsymbol{t}=mathbf{0} ) is :
( A )
( B )
( c )
( D )
11
350The string of a Sonometer is plucked so as to make it to vibrate in one segment The frequency produced in called.
( A ). first Harmonic
B. first Overtone
c. second Harmonic
D. second Overtone
11
351When we pluck the wire of a sitar, the waves produced in the air
are
A. longitudinal
B. transverse
c. sometimes longitudinal and sometimes transverse
D. electromagnetic
11
352There are four possible relative motions
between the source of a sound and the
listener
1) source moves towards stationary
listener
2) source moves away from stationary listener
3) listener moves towards stationary
source
4) listener moves away from stationary
source
In which of the cases, the change in frequency is the same. The magnitude of velocity of source or listener being
the same.
( A cdot 1 ) and 2
B. 2 and 3
( c cdot 3 ) and 4
D. 1 and 4
11
353Draw a sketch that shows the standing
waves pattern.
11
354When stationary waves are produced in a medium, which physical
characteristic change at antinodes?
A. Density only
B. Pressure only
c. Density and pressure
D. Neither density nor pressure
11
355The equation of a plane progressive wave is ( boldsymbol{y}=mathbf{0 . 9} sin mathbf{4} boldsymbol{pi}left[boldsymbol{t}-frac{boldsymbol{x}}{mathbf{2}}right], ) when it is
reflected at a rigid support, its amplitude becomes ( 2 / 3 ) of its previous value. The equation of the reflected wave is :
A ( cdot y=0.9 sin 4 pileft[t+frac{x}{2}right. )
B・ ( y=-0.6 sin 4 pileft[t+frac{x}{2}right] )
c. ( y=0.9 sin 8 pileft[t-frac{x}{2}right. )
D. ( y=0.6 sin 4 pileft[t+frac{x}{2}right] )
11
356Two whistles ( A ) and ( B ) produces notes of frequencies ( 600 mathrm{Hz} ) and ( 596 mathrm{Hz} ) respectively. There is a listener at the midpoint of the line joining them. Both
the whistles ( A, B ) and the listener start moving with speed ( 30 mathrm{m} / mathrm{s} ) in the same direction. If the speed of the sound is ( 330 mathrm{m} / mathrm{s} ), the number of beats that
will be heard by the listener are:
( A cdot 2 )
B. 4
( c cdot 6 )
D.
11
357A transverse progressive wave on a stretched string has a velocity of
( 10 m s^{-1} ) and frequency of ( 100 H z . ) The phase difference between two particles
of the string which nbare ( 2.5 mathrm{cm} ) apart will be :
A ( cdot frac{pi}{8} )
в.
c. ( frac{3 pi}{8} )
D. ( frac{pi}{2} )
11
358The distance between two consecutive
points in the same phase is called
A. Pitch
B. Velocity
c. wavelength
D. Period
11
359A string of length ( 20 mathrm{cm} ) and linear
mass density ( 0.4 g / c m ) is fixed at both ends and is kept under a tension of
16 ( N . ) A wave pulse is produced at ( t=0 )
near an end as shown in figure which travels towards the other end. The string have the shape shown in the figure ( operatorname{again} operatorname{in} 2 times 10^{-x} ) sec. Find ( x )
( A )
B.
( c )
D.
11
360Two trains are approaching each other on parallel tracks with same velocity.
The whistle sound produced by one train is heard by a passenger in another train. If actual frequency of whistle is
( 620 mathrm{Hz} ) and apparent increase in its frequency is ( 100 mathrm{Hz} ), the velocity of one of the two trains is (Velocity of sound in air ( left.=335 m s^{-1}right) )
A. 90kmph
B. 72 kmph
c. ( 54 mathrm{kmph} )
D. 36 kmph
11
361The maximum velocity of a body
undergoing S.H.M. is ( 0.2 m / s ) and its
acceleration at ( 0.1 mathrm{m} ) from the mean
position is ( 0.4 m / s^{-2} ) The amplitude of
the S.H.M. is:
A . ( 0.25 m )
в. ( 0.3 m )
( mathrm{c} .0 .1 mathrm{m} )
D. ( 1.05 m )
11
362A body is vibrating 7200 times in one minute. If the velocity of sound is 360 ( mathrm{m} / mathrm{s}, ) find (i) frequency of the vibration
in ( mathrm{Hz}, ) (ii) the wavelength of the sound
produced.
A. ( 120 mathrm{Hz}, 3 mathrm{m} )
в. ( 140 H z, 3 ) т
c. ( 120 H z, 4 m )
D. ( 140 H z, 4 m )
11
363When two identical wires on a
sonometer are kept under same tension, their fundamental frequency is ( 500 H z . ) In order to produce five beats per second, the percentage change in the tension of one of the wires will be:
A . ( 2 % )
B. ( 4 % )
( c .6 % )
D. ( 8 % )
11
364The displacement y of a wave traveling in the X-direction is given by ( boldsymbol{y}= ) ( 10^{-4} sin left(600 t-2 x+frac{pi}{3}right) ) metres. where
( x ) is expressed in metres and ( t ) in
seconds. The speed of the wave motion
( operatorname{in} m s^{-1} ) is:
A . 200
в. 300
c. 600
D. 1200
11
365When a sound is going away from a stationary observer with the velocity equal to that of sound in air, then the
frequency heard by observer is n times the original frequency. The value of n is
A. 0.5
B. 0.25
c. 1.0
D. no sound is heard
11
366toppr
Q Type your question
end, the shape of wave at time ( t=3 s ) is
( A )
B.
( c )
( D )
11
367Two particles move parallel to ( x ) -axis about the origin with same amplitude and frequency. At a certain instant they are found at a distance ( frac{a}{3} ) from the origin on opposite sides but their
velocities are found to be in same
direction.Then the phase difference between two particles will be
A ( cdot cos ^{-1}left(frac{7}{9}right) )
В. ( 180^{circ} )
c. ( 45^{circ} )
D. None of the above
11
368A boat at anchor is rocked by waves whose crests are 100 m apart and
velocity is 25 m/ sec. The boat bounces up once in every:
( mathbf{A} cdot 2500 s )
в. ( 75 s )
c. ( 4 s )
D. ( 0.25 s )
11
369Consider a sinusoidal travelling wave shown in figure. The wave velocity is ( +40 c m / s . ) The velocity of a particle at
point ( P ) at the instant shown is ( -126 times )
( 10^{-x} m / s . ) Find ( x )
4
B. 2
( c cdot 4 )
( D )
11
370Which of the following instruments can be used to measure the illuminating power of two sources?
A . Lactometer
B. Manometer
c. salinometer
D. Photometer
11
371The frequency of radio waves corresponding to a wavelength of ( 10 mathrm{m} )
is
( mathbf{A} cdot 3 times 10^{7} H z )
B ( .3 .3 times 10^{8} mathrm{Hz} )
( mathbf{C} cdot 3 times 10^{9} H z )
D. ( 3 times 10^{-7} mathrm{Hz} )
11
372i) From differential equation of linear
S.H.M., obtain an expression fro acceleration, velocity and displacement of a particle performing S.H.M.
ii) A sonometer wire 1 metre long
weighing ( 2 g ) in is resonance with a
turning fork of frequency ( 300 H z . ) Find tension in the sonometer wire.
11
373Two particles ( A ) and ( B ) execute simple
harmonic motion of periods ( boldsymbol{T} ) and ( mathbf{5} boldsymbol{T} / boldsymbol{4} )
They start from mean position. The phase difference between them when
the particle ( A ) completes an oscillation
will be?
( mathbf{A} cdot mathbf{0} )
в. ( frac{pi}{2} )
c.
D. ( frac{2 pi}{5} )
11
374If two waves of same frequency and amplitude respectively on superposition produce a resultant disturbance of the same amplitude, the wave differ in phase by :
( A )
B. zero
c. ( pi / 3 )
D. 2 ( pi / 3 )
11
375Sum of two mechanical waves
travelling in any direction (having the same frequency)
A. can be summed up to give a stationary wave
B. is added using the phasor diagramm
c. can have graphical representation with no troughs and elevations
D. none of the above
11
376If the energy density and velocity of a wave are ( u ) and ( c ) respectively then the
energy propagating per second per unit area will be
( mathbf{A} cdot u / c )
B . ( c^{2} u )
c. ( u )
D. ( c / u )
11
377The equation of wave is given by ( Y= )
( A sin omegaleft(frac{x}{v}-kright) ) where ( omega ) is the angular
velocity and v is the linear velocity. The dimensions of k is:
A . ( [L T] )
в. ( [T] )
( mathbf{c} cdotleft[T^{-1}right] )
( mathbf{D} cdotleft[T^{-2}right] )
11
378The equation ( y=4 sin pileft[200 t-left(frac{x}{25}right)right] )
represents a transverse wave that
travels in a stretched wire, where ( boldsymbol{x}, boldsymbol{y} )
are in ( c m ) and ( t ) in second.
Its wavelength and velocity are
A ( cdot 0.5 m, 25 m s^{-1} )
B . ( 0.5 m, 50 m s^{-1} )
c. ( 1 m, 50 m s^{-1} )
D. ( 1 m, 25 m s^{-1} )
11
379Explain why you can hear two people talking even when they walk around a
corner.
11
380In a mixture of gases, the average number of degrees of freedom per molecule is ( 6 . ) The rms speed of the molecules of the gas is ( c . ) The velocity of
sound in the gas is
A ( cdot frac{c}{sqrt{2}} )
в. ( frac{3 c}{4} )
c. ( frac{2 c}{3} )
D. ( frac{c}{sqrt{3}} )
11
381A uniform horizontal rod of length ( 40 mathrm{cm} ) and mass ( 1.2 mathrm{kg} ) is supported by
two identical wires as shown in the
figure. Where should a mass of ( 4.8 k g )
be placed on the rod from the left end (in
( mathrm{cm} ) so that the same tuning fork may
excite the wire on left into its
fundamental vibrations and that on
right into its first overtone? Take ( G= )
( 10 m / s^{2} )
11
382The velocity of sound in air is ( V ) and the
root mean square velocity of the molecules is ( c ). The ( V / c= )
A ( cdot frac{gamma}{3} )
в. ( quadleft[frac{gamma}{3}right]^{frac{1}{2}} )
c. ( frac{gamma}{sqrt{3}} )
D. ( frac{sqrt{gamma}}{3} )
11
383A police car moving at ( 22 mathrm{m} / mathrm{s} ), chase a motorcyclist. The police man sounds his horn at ( 176 mathrm{Hz} ), while both of them move
towards a stationary siren of frequency ( 165 mathrm{Hz} . ) Calculate the speed of the motorcyclist, if he does not observe any beats. (velocity of sound in air ( =330 ) ( mathrm{m} / mathrm{s}) )
[
begin{array}{l}
text { Police car } \
hline 176 mathrm{Hz}^{*} 22 mathrm{m} / mathrm{s} frac{text { Motorcycle }}{mathrm{V}} quad text { Stationary } \
qquad text { Siren }(165 mathrm{Hz})
end{array}
]
( A .33 mathrm{m} / mathrm{s} )
B. 22 m/s
c. zero
D. ( 11 mathrm{m} / mathrm{s} )
11
384A travelling wave has a velocity of 400 ( mathrm{m} / mathrm{s} ) and has a wavelength of ( 0.5 mathrm{m} ) What is the phase difference between two points in the wave that are 1.25 milli
secs apart
A ( .2 pi )
в. ( 2 pi / 3 )
c. ( 2 pi / 5 )
D. ( pi / 6 )
11
385the wavelength11
386State whether true or false:
Speed of sound can never exceed the
average molecular speed in a fluid.
A. True
B. False
11
387the diagram shows the propagation of a
wave. Which points are in same phase?
( A cdot F ) and ( G )
B. ( C ) and ( E )
( mathrm{C} cdot mathrm{B} ) and ( mathrm{G} )
D. ( B ) and ( F )
11
388Two coherent waves are represented by
( boldsymbol{y}_{1}=boldsymbol{a}_{1} cos omega t ) and ( boldsymbol{y}_{2}=boldsymbol{a}_{2} sin omega t . ) The
resultant intensity due to interference will be
B. ( left(a_{1}^{2}+a_{2}^{2}right) )
c. ( left(a_{1}-a_{2}right) )
and
D ( cdotleft(a_{1}+a_{2}right) )
11
389The wave produced in a resonance tube
is
A . Longitudinal
B. Transverse
c. Transverse stationary
D. Longitudinal stationary
11
390A wave of amplitude ( 10 mathrm{cm} ) and frequency 1000 Hz is travelling with a velocity of ( 300 mathrm{m} / mathrm{s} ). Calculate the phase difference of a particle at a distance of ( 3 mathrm{m} ) from the origin after ( 1.001 mathrm{s} )11
391The equation for the reflected wave is ( operatorname{given} operatorname{as} y_{2}=pm frac{s}{10} A cos (a x-b t) ) Find
( mathcal{S} )
11
392The wavelength of monochromatic light is ( 5000 A ) in air what will be its wave
number in a medium of refractive index
( mathbf{1 . 5} ? )
A ( cdot 3 times 10^{6} m^{-1} )
В. ( 5 times 10^{6} m^{-1} )
c. ( 2 times 10^{6} m^{-1} )
D. ( 9 times 10^{6} m^{-1} )
11
393Choose the correct statement:
A. The wave velocity is less than phase velocity of the wave
B. The particle velocity is the same as phase velocity of the wave
C. The particle velocity is the same as group velocity of the wave
D. The wave velocity is the same as group velocity of the wave
11
394toppr
Q Type your question
is given by ( y=f(x-150 t) ) where ( x ) is in
meters and t is in seconds.

The pulse (y) is plotted as a function of
( x ) for ( t=0 . ) Draw the pulse (in the panels
given)
(i) as a function of ( x ) for ( t=0.04 s )
(ii) as a function of ( t ) for ( x=0 )
A ( cdot V=150 mathrm{m} / mathrm{s} ; quad x=v t ; quad x=150 times frac{4}{100}=6 mathrm{cm} )
B. ( V=120 mathrm{m} / mathrm{s} ; quad x=v t ; quad x=150 times frac{4}{100}=6 mathrm{cm} )
( mathrm{C} cdot mathrm{V}=150 mathrm{m} / mathrm{s} ; quad x=v t ; x=120 times frac{4}{100}=6 mathrm{cm} )
( V=150 m / s ; quad x=v t ; x=150 times frac{4}{100}=5 mathrm{cm} )

11
395What will be the wave velocity, if the radar gives 54 waves per min and
wavelength of the given wave is ( 10 mathrm{m} ? )
( A cdot 4 mathrm{m} mathrm{s}^{-1} )
B. ( 6 mathrm{m} mathrm{s}^{-1} )
( c cdot 9 m s^{-1} )
( D cdot 5 mathrm{m} mathrm{s}^{-1} )
11
396A person with vibrating tuning fork of frequency ( 338 mathrm{Hz} ) is moving towards a
vertical wall with a speed of ( 2 m s^{-1} )
Velocity of sound in air is ( 340 m s^{-1} ). The
number of beats heard by that person per second is.
A . 2
B. 4
c. 6
D.
11
397( boldsymbol{y}(boldsymbol{x}, boldsymbol{t})=mathbf{0 . 8} /left[(boldsymbol{4} boldsymbol{x}+boldsymbol{5} boldsymbol{t})^{2}+mathbf{5}right] )
represents a moving pulse, where ( x ) and
( y ) are in meter and ( t ) in second. Then
This question has multiple correct options
A. pulse is moving in ( +x ) direction
B. in ( 2 s ) it will travel a distance of 2.5 m
c. its maximum displacement is 0.16 m
D. it is symmetric pulse
11
398The phenomenon of interference is
shown by
A. longitudinal mechanical waves only
B. transverse mechanical waves only
C. non mechanical transverse waves only
D. all the above types of waves
11
399Two rods ( P ) and ( Q ) are considered such
that Young’s modulus of elasticity of rod ( P ) is twice that of the other while the
density of rod ( Q ) is eighteen times that of rod P. If a sound wave is allowed to
transverse ( 2 mathrm{m} ) distance through each rod, then by how many times the time taken through ( P ) is less than that of ( Q ? )
A. 2 times
B. 3 times
c. 4 times
D. 5 times
11
400Compression and rarefaction are seen
in
A. Transverse waves
B. Non mechanical waves
c. Longitudinal waves
D. None
11
401A person is seeing two trains one of there is coming with speed of ( 4 mathrm{m} / mathrm{s} ) and another is going with same speed. If two trains blowing a whistle with frequency 243Hz . The beat frequency heard by stationary person will be (speed of sound in air ( =320 mathrm{m} / mathrm{s} )
в. ( 3 H z )
( mathrm{c} .6 mathrm{Hz} )
D. ( 12 H z )
11
402The equation of a travelling wave is given by ( boldsymbol{y}=mathbf{1 0} cos left[frac{boldsymbol{pi} boldsymbol{t}}{mathbf{3}}+boldsymbol{alpha}right] . ) If the
displacement is ( 10 mathrm{cm} ) at ( t=0, ) then the
total phase at ( t=1.5 s ) will be
A ( cdotleft(frac{2 pi}{3}right) r a d )
в. ( (2 pi) ) rad
c. ( left(frac{pi}{3}right) r a d )
D. ( left(frac{2 pi}{6}right) r a d )
11
403An open pipe of length ( 33 mathrm{cm} ) resonates with frequency of ( 1000 H z ). If the speed
of sound is ( 330 m s^{-1}, ) then this
frequency is
A. The fundamental frequency of the pipe
B. The first harmonic of the pipe
c. The second harmonic of the pipe
D. The forth harmonic of the pipe
11
404The propagation constant of wave is also called its
A. wavelength
B. frequency
c. wave number
D. angular wave number
11
405The equation of a wave is given by ( boldsymbol{Y}= ) ( 5 sin 10 pi(t-0.01 x) ) along the ( x ) -axis.
(All the quantities are expressed in ( mathrm{S} ) ) units ( } . ) The phase difference the points separated by a distance of ( 10 mathrm{m} ) along ( mathrm{x} ) axis is
A ( cdot frac{pi}{2} )
в. ( pi )
( c cdot 2 pi )
D. ( frac{pi}{4} )
11
406Transverse waves on a string have wave speed ( 12.0 mathrm{m} / mathrm{s}, ) amplitude ( 0.05 mathrm{m} ) and
wavelength 0.4 m. The waves travel in
the ( +x ) direction and at ( t=0, ) the ( x=0 )
end of the string has zero displacement and is moving upwards. Write a wave function describing the wave.
11
407A travelling wave pulse defined as ( y= ) ( frac{10}{5+(x+2 t)^{2}} . ) In which direction and
with what velocity is the pulse propagating?
11
408The angular frequency of motion whose equation is ( 4 frac{d^{2} y}{d t^{2}}+9 y=0 ) is ( (y= )
displacement and ( t= ) time
A ( cdot frac{9}{4} )
в. ( frac{4}{9} )
( c cdot frac{3}{2} )
D. ( frac{2}{3} )
11
409A boy blowing a whistle, is running away from a wall towards an observer with a
speed of 1 ms ( ^{-1} ). The frequency of
whistle is ( 680 mathrm{Hz} ). The number of beats
heard per second by the observer will be
( left(operatorname{given} v=340 m s^{-1}right) )
A. zero
B. 2
( c cdot 4 )
D. 8
11
410The wave that propagates as an oscillation of matter, and therefore
transfers energy through a medium is
A. Mechanical wave
B. Ultrasonic wave
c. Infrared wave
D. None
11
411Two coherent waves are represented by
( boldsymbol{Y}_{1}=boldsymbol{A}_{1} cos omega t . boldsymbol{Y}_{2}=boldsymbol{A}_{2} sin omega boldsymbol{t} )
The resultant intensity due to
interference is proportional to
A ( cdotleft(A_{1}+A_{2}right) )
В ( cdotleft(A_{1}-A_{2}right) )
( mathbf{c} cdotleft(A_{1}^{2}+A_{2}^{2}right) )
D ( cdotleft(A_{1}^{2}-A_{2}^{2}right) )
11
412The wave equation is ( y= ) ( 0.30 sin (314 t-1.57 x) ) where ( t, x ) and ( y )
are in second, metre and centimetre
respectively. The speed of the wave is
A. ( 400 mathrm{m} / mathrm{s} )
в. ( 100 mathrm{m} / mathrm{s} )
c. ( 200 m / s )
D. ( 50 mathrm{m} / mathrm{s} )
11
413The wave function of a pulse is given by ( y=frac{5}{(4 x+6 t)^{2}} ) where ( x ) and ( y ) are in
meter and ( t ) is in second, then
determine the wave velocity of the
pulse.
A. ( 2 m / s )
в. ( 1 mathrm{m} / mathrm{s} )
c. ( -1.5 m / s )
D. ( 2.5 mathrm{m} / mathrm{s} )
11
414Let ( n_{1}, n_{2}, n_{3} dots ) are the frequencies of
segments of a stretched string, then the frequency ( n ) of the string can be given
by
A ( cdot n=n_{1}+n_{2}+n_{3}+dots )
B. ( n=sqrt{n_{1} times n_{2} times n_{3} times ldots} )
c. ( frac{1}{n}=frac{1}{n_{1}}+frac{1}{n_{2}}+frac{1}{n_{3}}+dots )
D. None of the above
11
415For a stationary wave ( boldsymbol{y}= ) ( 4 sin left(frac{pi x}{15}right) cos (96 pi t), ) the distance
between a node and the next antinodes
is.
A . 7.5
B . 15
c. 22.5
D. 30
11
416A train is approaching the platform with a speed of ( 4 m s^{-1} ). Another train is
leaving the platform with the same
speed. The velocity of sound is ( 320 m s^{-1} )
If both the trains sound their whistles
at frequency ( 230 mathrm{Hz} ), the number of beats heard per second will be :
( A cdot 10 )
B. 8
c. 7
D. 6
11
41720 tuning forks are so arranged in series that each fork gives 4 bets per second with the previous one.The frequency of the 20 th fork is three times that of the first. What is the frequency of the first tuning fork?
( A cdot 60 ) Н
B. 57 Н
c. 40 нz
D. 38 нz
11
418Assertion
Assertion: When a light wave travels
from a rarer to a denser medium, its
speed decreases. The decrease in speed
imply a reduction in energy carried by the light wave.
Reason
Reason: The energy of a wave is inversely proportional to velocity of
wave
A. If both assertion and reason are true and reason is the correct explanation of assertion
B. If both assertion and reason are true and reason is not the correct explanation of assertion.
c. If assertion is true but reason is false
D. If both assertion and reason are false
11
419A travelling wave has an equation of the form ( boldsymbol{A}(boldsymbol{x}, boldsymbol{t})=boldsymbol{f}(boldsymbol{x}+boldsymbol{v} boldsymbol{t}) . ) The relation
connecting positional derivative with
time derivative of the function is:
A ( cdot frac{d A}{d t}=pm v^{2} frac{d A}{d x} )
в. ( frac{d A}{d t}=pm v frac{d A}{d x} )
c. ( left.frac{d A}{d t}=pm sqrt{(} vright) frac{d A}{d x} )
D. ( frac{d A}{d t}=(2 pi v / lambda) frac{d A}{d x} )
11
420A wave of frequency ( 400 H z ) has a
velocity of ( 320 m s^{-1} . ) The distance between the particles differing in phase
by ( 90^{circ} ) is
( mathbf{A} cdot 80 mathrm{cm} )
B. ( 60 mathrm{cm} )
c. ( 40 mathrm{cm} )
D. ( 20 mathrm{cm} )
11
421Equations of a stationary wave and a
travelling wave are ( boldsymbol{y}_{1}=boldsymbol{a} ) sink ( boldsymbol{x} ) coswt
and ( y_{2}=a sin (omega t-k x) . ) The phase
difference between two points ( boldsymbol{x}_{1}= ) ( frac{pi}{3 k} ) and ( x_{2}=frac{3 pi}{2 k} i s phi_{1} ) for the first
wave and ( phi_{2} ) for the second wave. The
ratio ( frac{phi_{1}}{phi_{2}} ) is :
A. 1
в. ( frac{5}{6} )
( c cdot frac{3}{4} )
D. ( frac{6}{7} )
11
422A mechanical wave needs
for propogating
energy
A. a set of photons
B. a set of electrons
c. a medium
D. water
11
423Equation of 251 mpu harmonic progression wave arriving at a point in the medium simultaneously ( boldsymbol{y}_{1}=mathbf{0 . 0 5} sin 2 pileft(mathbf{5 0 t}-frac{boldsymbol{x}}{boldsymbol{lambda}}right) boldsymbol{m} )
( boldsymbol{y}_{2}=mathbf{0 . 0 5} sin 2 pileft(mathbf{5 5 t}-frac{boldsymbol{x}}{mathbf{2}}right) boldsymbol{m} )
Calculate wavelength of first wave and beat frequency when sounded together.
11
424Which of the following does not represent a standing wave
A ( . y=A sin omega x cos omega t )
B. ( y=A sin omega x sin omega t )
c. ( y=A cos omega x cos omega t )
D. none
11
425The displacement ( y ) of a particle in a medium can be expressed asy ( = ) ( mathbf{1 0}^{-6} sin left(mathbf{1 1 0 t}+mathbf{2 0 x}+frac{boldsymbol{pi}}{mathbf{4}}right) mathbf{m}, ) where ( mathbf{t} ) is
in second and ( x ) in metre. The speed of
the wave is
A ( .2000 mathrm{m} / mathrm{s} )
B. ( 5 mathrm{m} / mathrm{s} )
c. ( 20 mathrm{m} / mathrm{s} )
D. ( 5 pi mathrm{m} / mathrm{s} )
11
426If two waves of same frequency and same amplitude, on superposition, produce a resultant disturbance of the
same amplitude, the wave differ in phase by
( A )
в. ( 2 pi / 3 )
c. zero
D. ( pi / 3 )
11
427A wire of length ( 1 m ) and mass ( 20 g ) is stretched with a force of ( 800 N ). The
frequencies of the first two overtones
are
A. ( 200 H z, 300 H z )
в. ( 300 H z, 200 H z )
c. ( 100 H z, 400 H z )
D. ( 400 H z, 100 H z )
11
428When a sound wave of frequency ( 300 mathrm{Hz} ) passes through medium, the maximum displacement of a particle of the
medium is ( 0.1 mathrm{cm} . ) The maximum
velocity of the particle is equal to.
( mathbf{A} cdot 60 pi mathrm{cm} / mathrm{s} )
B. ( 30 pi mathrm{cm} / mathrm{s} )
( mathrm{c} cdot 60 mathrm{cm} / mathrm{s} )
D. ( 30 mathrm{cm} / mathrm{s} )
11
429The displacement of a particle
executing SMH is given by ( boldsymbol{x}= ) ( 0.01 sin 100 pi(t+0.05) . ) The time
period is
A . 0.01 sec
B. 0.02 sec
c. ( 0.1 mathrm{sec} )
D. ( 0.2 sec )
11
430A source of sound moves towards a
listener with a velocity equal to that of
sound. If the source emits n waves per
second, then the listener moving away from the source with the same velocity receives
A. n waves per sec
B. 2n waves per sec
c. zero waves per sec
D.
11
431The points moving downwards is/are
( A )
( B )
( c cdot d )
D
11
432Identify which one of the following can be represented by the product of the
other two?
I. Speed
Il. Wavelength
III. Frequency
( A )
B. I
c. ॥
D. Any one is the product of the other two
E. None of the three is the product of the other two
11
433A steel wire of length ( 64 mathrm{cm} ) weighs ( 5 mathrm{g} ). It
is stretched by a force of ( 8 N, ) what
would be the speed of transverse wave passing on it?
11
434A sinusoidal wave travelling in the positive direction of ( x ) on a stretched string has amplitude ( 2.0 mathrm{cm} ) wavelength ( 1 mathrm{m} ) and wave velocity 5.0 ( mathrm{m} / mathrm{s} cdot mathrm{At} mathrm{x}=0 ) and ( mathrm{t}=0, ) it is given that
displacement ( y=0 ) and ( frac{partial y}{partial t}<0 . ) Express the wave function correctly in the from ( y ) ( =f(x, t):- )
A ( cdot y=(0.04 mathrm{m})left[sin left(pi m^{-1} 1right) mathrm{x}-left(10 pi s^{-1} 1right) tright] )
B. ( y=(0.02 mathrm{m}) cos 2 pi(x-5 t) )
c. ( y=(0.02 mathrm{m})left[sin left(2 pi m^{-1} 1right) x-left(10 pi s^{-1}right)right] t )
D ( cdot y=(0.02 mathrm{m}) cos pileft(x-5 t+frac{1}{4}right) )
11
435A person has a tuning fork that sounds with a frequency of ( 250 H z . ) The person strikes the fork and plays a white key that sounds with a frequency of ( 220 H z ) Calculate the beat frequency that the piano person hears?
A. ( 0 H z )
( z )
B. ( 0.8 mathrm{Hz} )
c. ( 1.25 H z )
D. ( 30 H z )
E . ( 450 mathrm{Hz} )
11
436Two vibrating strings of the same
material but length ( L ) and ( 2 L ) have radii
( 2 r ) and ( r ) respectively. They are
stretched under the same tension. Both
the string vibrate in their fundamental
modes, the one of length ( L ) with
frequency ( v_{1} ) and other with frequency
( boldsymbol{v}_{2} . ) The ratio ( boldsymbol{v}_{1} / boldsymbol{v}_{2} ) is given by
A . 2
B. 4
c. 8
D.
11
437Working of radars in oceans is based on
the principle of
A . geo-positional system
B. reflection of sound
c. locus of sound waves
D. none
11
438A uniform string of length ( L ) fixed between the two ends is vibrating in three segments. The wavelength of wave in string is
A ( cdot frac{L}{3} )
в. ( 3 L )
c. ( frac{2 L}{3} )
D. ( frac{3 L}{2} )
11
439The equation of a stationary wave is ( Y= ) ( 10 sin sin frac{pi x}{4} cos 20 pi t . ) The distance
between two consecutive antinodes in
meters is –
A . 4
B. 2
( c cdot 5 )
D. 8
11
440The equation of a wave disturbance is
given as : ( boldsymbol{y}= ) ( 0.02 cos left(frac{pi}{2}+50 pi tright) cos (10 pi x), ) where
( x ) and ( y ) are in meters and ( t ) in seconds.
Choose the wrong statement:
A. Antinode occurs at ( X=0.3 m )
B. The wavelength is ( 0.2 mathrm{m} ).
c. The speed of the constituent waves is ( 4 m / s )
D. Node occurs at ( X=0.15 mathrm{m} )
11
441topp
ge eva
11
442Assertion
Sound shadows are generally not so well defined as those of light.
Reason
The wavelength of sound waves are very large in comparison to that of light
waves.
A. Statement 1 is True and Statement 2 is True and is correct explanation of statement 1
B. Statement 1 is True and Statement 2 is True but not correct explanation for Statement
c. Statement 1 is True and Statement 2 is False.
D. Statement 1 is False and Statement 2 is True
11
443The kinetic energy per unit length for a wave on a string is the positional
coordinate
A. True
B. False
11
444When viewed in white light, soap bubble show colors because of
A . Interference
B. Scattering
c. Diffraction
D. Dispersion
11
445In a medium in which a transverse
progressive wave is travelling the phase difference between two points with a distance of separation ( 1.25 mathrm{cm} ) is ( frac{pi}{4} . )
the frequency of the wave is ( 1000 H z )
its velocity will be
A ( cdot 10^{4} m / s )
в. ( 125 mathrm{m} / mathrm{s} )
c. ( 100 m / s )
D. ( 10 mathrm{m} / mathrm{s} )
11
446A source ( x ) of unknown frequency produces 8 beats with a source of 250 ( mathrm{Hz} ) and 12 beats with a source of ( 270 mathrm{Hz} )
The frequency of source x is
A. 258 Hz
B. 242 нz
c. 262 н
D. 282 нz
11
447Consider the wave and choose the
correct option
A. blue wave has higher frequency
B. red wave has higher frequency
C. blue wave has higher time period
D. none of the above
11
448The resultant amplitude, when two
waves of same frequency but with
amplitudes ( a_{1} ) and ( a_{2} ) superimpose with a phase difference of ( pi / 2 ) will be
A ( cdot a_{1}^{2}+a_{2}^{2} )
B ( cdot sqrt{a_{1}^{2}+a_{2}^{2}} )
c ( cdot a_{1}-a_{2} )
D. ( a_{1}+a_{2} )
11
449The amplitude of the two travelling waves that make up this standing wave
is ( 2.80 times 10^{-x} ) m. Find ( x )
11
450The phase difference between the particle at one compression and another particle in third compression is
( A cdot pi ) radians
B. 2 ( pi ) radians
c. ( 3 pi ) radians
D. ( 4 pi ) radians
11
451Calculate by how much will the sound
level decrease if the observer moves
from a distance of ( 2 mathrm{m} ) to a distance of
( 20 mathrm{m} ) from the source.
( A cdot 1 d B )
B. 2 dB
( c cdot 10 d B )
D. 18 dB
E . ( 20 d B )
11
452What do you understand by the term
wave?
11
453A source of wave produces 3 crests and
3 troughs in ( 2 m s, ) the frequency of the
wave is
A. ( 1250 H z )
в. ( 1500 H z )
с. ( 1000 H z )
D. ( 750 H z )
11
454A wave is represented by an equation; ( Y=A cos k x sin omega t, ) then
A. It is a progressive wave with amplitude ( A )
B. It is a progressive wave with amplitude ( A ) cos ( k x )
c. It is a stationary wave with amplitude ( A )
D. It is a stationary wave with amplitude ( A cos k x )
11
455A string fastened at both ends has
successive resonances with
wavelengths of ( 0.54 m ) for the ( n^{t h} )
harmonic and ( 0.48 m ) for the ( (n+1)^{t h} )
harmonic. The wavelength of the fundamental frequency is ( 432 times 10^{-x} m )
What is the value of ( x ? )
A . 1
B. 2
( c .3 )
D.
11
456The frequency of a sonometer wire is ( f ) The frequency becomes f/2 when the mass producing the tension is completely immersed in water and on immersing the mass in a certain liquid, frequency become f/3. The relative
density of the liquid is
A . 1.32
B . 1.67
( c cdot 1.4 )
D. 1.18
11
457What will be the wave velocity, if the
radar gives 54 waves per min and wavelength of the given wave is ( 10 m ? )
( mathbf{A} cdot 4 m s^{-1} )
B. ( 6 m s^{-1} )
( mathrm{c} cdot 9 m s^{-1} )
D. ( 5 m s^{-1} )
11
458Which wave will have larger energy:
A. High frequency
B. Large amplitude
c. Both A and B
D. None of the above
11
459Newton’s formula for the velocity of
sound in gas is
( ^{mathrm{A}} cdot_{v}=sqrt{frac{P}{rho}} )
в. ( _{v}=frac{2}{3} sqrt{frac{P}{rho}} )
c. ( v=sqrt{frac{rho}{P}} )
D. ( v=sqrt{frac{2 P}{rho}} )
11
460A uniform rope of length ( 12 mathrm{m} ) and mass 6 kg hangs vertically from a rigid support. A block of mass 2 kg is attached to the free end of the rope. ( A )
transverse pulse of wavelength ( 0.06 mathrm{m} ) is produced at the lower end of the rope.
What is the wavelength of the pulse
when it reaches the top of the rope?
A. ( 0.06 mathrm{m} )
B. 0.03
c. ( 0.12 mathrm{m} )
D. 0.09 ( m )
11
461Frequency (v) and time period (T) are related as
A ( . v times T=1 )
B. ( frac{v}{T}=1 )
c. ( v=T^{2} )
D ( cdot v=T^{-2} )
11
462The particle of a medium vibrates about their mean position whenever a wave travels through that medium. The phase
difference between the vibrations of two
such particles
A. varies with time only
B. varies with distance separating them only
c. varies with time as well as distance
D. is always zero
11
463In above shown figure, two speaker, ( boldsymbol{S}_{1} )
and ( S_{2} ) are kept at ( 3 mathrm{m} ) apart. Speakers emit a sound wave of wavelength of ( mathrm{m} ) Emitted waves are in phase with each other. Compare the amplitude of
resulting wave at point ( P ) and ( Q ) if ( A_{P} )
and ( A_{Q} ) resulted amplitude at point ( P ) and ( Q ) respectively.
A. ( A_{P}A_{Q} )
D. ( A_{P}0 )
E. ( A_{P} ) and ( A_{Q} ) vary with times, so no comparison can be made
11
464A man generates a symmetrical plus in a string by moving his hand up and down. At ( t=0 ) the point in his hand
moves downward. The pulse travels with speed ( 3 m / s ) on the string ( & ) his hands
passes 6 times in eacgh seconds from the mean position. Then the point on the string at a distance ( 3 m ) will reach its upper extreme first time at time ( t= )
A. 1.25 sec
в. 1 sec
( mathbf{c} cdot frac{13}{12} sec )
D. None
11
465The equation of the transverse wave travelling in a rope is given by ( mathbf{y}= ) ( 5 sin (4 t-0.02 x) ) where ( y ) and ( x ) are in
meters and ( t ) is in seconds. Calculate
the intensity of the wave if the density
of rope material is ( 1250 mathrm{kg} / mathrm{m}^{3} )
A. ( 2000 mathrm{kJm}^{-2} mathrm{s}^{-1} )
B. ( 10 mathrm{kJm}^{-2} mathrm{s}^{-1} )
c. ( 40 mathrm{kJm}^{-2} mathrm{s}^{-1} )
D. 3 ( k J m^{-2} s^{-1} )
11
466If two waves of length ( 50 mathrm{cm} ) and ( 51 mathrm{cm} )
produced 12 beats per second, the
velocity of sound is:
A . 360
в. 340
( c .306 )
D. none of the above
11
467Two source of sound placed closed to each other, are emitting progressive
wave given by ( y_{1}=4 sin 600 pi t ) and
( boldsymbol{y}_{2}=mathbf{5} sin mathbf{6 0} mathbf{8} boldsymbol{pi} boldsymbol{t} . ) An observed located
near these two sources will hear:
A. 8 beats per second with intensity ratio 81: 1 between waxing and waning
B. 4 beats per second with intensity ratio 81: 1 between waxing and waning
c. 4 beats per second with intensity ratio 25: 16 between waxing and waning
D. 8 beats per second with intensity ratio 25 : 16 between waxing and waning
11
468The equation ( y=A sin ^{2}(k x-omega t) )
represents a wave with
A. amplitude A frequency ( omega / 2 pi )
B. amplitude A /2 frequency ( omega / pi )
c. amplitude 2A frequency ( omega / 4 pi )
D. It does not represent a wave motion
11
469An object is vibrating at 50 hertz. What is its time period?
A . ( 0.02 mathrm{s} )
B. 0.2
( c cdot 2 s )
D. 20.0
11
470A wave of frequency 500 Hz has a wave velocity of ( 350 mathrm{m} / mathrm{s} ). The distance
between two points which point are ( 60^{circ} )
out of phase is ( 116 times 10^{-x} m . ) Find ( x )
11
471Two open pipes of length ( 50 mathrm{cm} ) and 51
cm produce 6 beats when sounded together, find the speed of sound:
A ( cdot 330 m s^{-1} )
B. ( 316 mathrm{ms}^{-1} )
c. ( 306 m s^{-1} )
D. ( 360 mathrm{ms}^{-1} )
11
472The equation of a wave disturbance is given as:
( y=0.02 sin left(frac{pi}{2}+50 pi tright) cos (10 pi x) )
where ( x ) and ( y ) are in metres and ( t ) is in
seconds.
Choose the correct statement(s):
This question has multiple correct options
A. the wavelength of wave is ( 0.2 m )
B. displacement node occurs at ( x=0.15 mathrm{m} )
c. displacement antinode occurs at ( x=0.3 mathrm{m} )
D. the speed of constituent waves is ( 0.2 mathrm{m} / mathrm{s} )
11
473A wire of length ( L ) and mass per unit
length ( 6.0 times 10^{-3} k g m^{-1} ) is put under
tension of ( 540 mathrm{N} ). Two consecutive
frequencies that it resonates at are:
( 420 H z ) and ( 490 H z . ) Then ( L ) in meters
is:
( mathbf{A} cdot 1.1 m )
B. ( 5.1 mathrm{m} )
c. ( 2.1 m )
D. ( 8.1 mathrm{m} )
11
474A chord attached to a vibrating form divides it into 6 loops, when its tension
is ( 36 N . ) The tension at which it will
vibrate in 4 loops is
A ( .24 N )
в. ( 36 N )
( c cdot 64 N )
D. ( 81 N )
11
475The speed of transverse wave on a
stretched string is:
A. directly proportional to the tension in the string
B. directly proportional to the square root of the tension
C. inversely proportional to tension
D. inversely proportional to square root of tension
11
476Explain the formation of stationary waves by analytical method. Show that nodes and antinodes are equally spaced in stationary waves.11
477Newton assumes that sound
propagation in gas takes under
A. isothermal condition
B. adiabatic condition
c. isobaric condition
D. isentropic condition
11
478A transverse sinusoidal wave of
amplitude a, wavelength ( lambda ) and frequency ( boldsymbol{f} ) is travelling on a stretched string. The maximum speed of any point on the string is ( frac{v}{10}, ) where ( v ) is the
speed of propagation of the wave. If ( boldsymbol{a}= )
( 10^{-3} m ) and ( v=10 mathrm{m} / mathrm{s}, ) then ( lambda ) is given
by This question has multiple correct options
( mathbf{A} cdot lambda=2 pi times 10^{-2} m )
B. ( lambda=10^{-3} m )
C ( . lambda=pi times 10^{-2} )
D. ( lambda=2 pi times 10^{-3} )
11
479The number of beats produces per second by two tuning forks when sounded together is ( 4 . ) One of them has frequency of ( 250 H z . ) The frequency of
the other cannot be less than
A ( .254 mathrm{Hz} )
B. 252 H
( mathrm{c} .248 mathrm{Hz} )
D. 246 ( H z )
11
480State whether the given statement is
True or False:

Consider a sinusoidal travelling wave
shown in figure. The wave velocity is ( +40 c m / s . ) The phase difference
between points ( 2.5 mathrm{cm} ) apart will be ( frac{mathrm{b} pi}{4} )
rad
A. True
B. False

11
481A particle in SHM is described by the displacement function: ( boldsymbol{x}(boldsymbol{t})= ) ( boldsymbol{A} cos (boldsymbol{omega} boldsymbol{t}+boldsymbol{phi}) . ) If the initial ( (boldsymbol{t}=mathbf{0}) )
position of the particle is ( 1 mathrm{cm} ) and its initial velocity is ( omega mathrm{cm} / mathrm{sec}, ) what is the
initial phase angle? This question has multiple correct options
A ( cdot frac{3 pi}{4} )
в. ( frac{7 pi}{4} )
c. ( frac{7 pi}{2} )
D. ( frac{pi}{4} )
11
482A radar sends a signal to an aircraft at a distance of ( 30 k m ) away and receives it
back after ( 2 times 10^{-4} ) second. What is the
speed of the signal?
11
483assertion – The interference of two
identical waves moving in same direction produces standing waves. Reason – Various elements of standing waves do not remain in constant phase.
A. Assertion and Reason are correct and Reason is the correct explanation for Assertion
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
c. Assertion is correct but Reason is incorrect
D. Both Assertion and Reason are incorrect
11
484The product of the time period of a wave and its frequency is
A . Infinite
B. Zero
c. More than unity but less than infinity
D. Unity
11
485Mechanical waves are generated, when
the disturbance is
A. generated in vacuum and propagates in the space.
B. generated in elastic mediums and propagates in the space
C. generated by photons and propagates in space.
D. generated by electrons and propagates in the space.
11
486The distance between two points
differing in phase by ( 60^{circ} ) on a wave
having a wave velocity ( 360 m / s ) and frequency ( 500 H z ) is
A . ( 0.72 mathrm{m} )
B. ( 0.18 m )
c. ( 0.12 m )
D. 0.36 m
11
487Two stretched strings have lengths and 21 while tension are T and 4T
respectively. If they are made of same material the ratio of their frequency is:
A. 2:
B. 1: 2
( c cdot 1: 1 )
( D cdot 1: 4 )
11
488The equation of a transverse wave travelling along positive ( X ) axis with amplitude ( 0.2 m, ) velocity ( 360 m / s ) and wavelength 60 m can be written as:
A ( cdot y=0.2 sin pileft[6 t+frac{x}{60}right] )
B. ( y=0.2 sin pileft[6 t-frac{x}{60}right] )
c. ( y=0.2 sin 2 pileft[6 t-frac{x}{60}right] )
D. ( y=0.2 sin 2 pileft[6 t+frac{x}{60}right. )
11
489A rope, under a tension of ( 200 N ) and
fixed at both ends, oscillates in a second-harmonic standing wave pattern. The displacement of the rope is given by ( : boldsymbol{y}=mathbf{0 . 1} sin left(frac{pi x}{2}right) sin 12 pi t )
Where ( x=0 ) at one end of the rope, ( x ) is in meters and ( t ) is in seconds. The length
of the rope is
11
490The wavelength of a spectral line
coming from a star is changed by the motion of the star from 6000 A to 6001
A. What is the velocity of the star with respect to earth? (The velocity of light is ( 3 times 10^{8} mathrm{m} / mathrm{sec} )
A ( cdot 5 times 10^{4} mathrm{m} / mathrm{sec} ) receding
B. ( 5 times 10^{4} mathrm{m} / mathrm{sec} ) approaching
c. ( 3 times 10^{4} mathrm{m} / ) sec receding
D. 3 ( times 10^{4} mathrm{m} / ) sec approaching
11
491( boldsymbol{y}_{1}=mathbf{8} boldsymbol{8} sin (boldsymbol{omega} boldsymbol{t}-boldsymbol{k} boldsymbol{x}) ) and ( boldsymbol{y}_{2}= )
( 6 sin (omega t+k x) ) are two waves travelling
in a string of area of cross-section ( s ) and
density ( rho . ) These two waves are
superimposed to produce a standing
wave. Find the total amount of energy
crossing through a node per second.
A ( cdot frac{2 rho omega^{3} s}{k} )
B. ( frac{3 rho omega^{3} s}{k} )
c. ( frac{5 rho omega^{3} s}{k} )
D. ( frac{6 rho omega^{3} s}{k} )
11
492The equation of a progressive wave for a
wire is:
( boldsymbol{Y}=mathbf{4} sin left[frac{boldsymbol{pi}}{mathbf{2}}left(boldsymbol{8} boldsymbol{t}-frac{boldsymbol{x}}{boldsymbol{8}}right)right] . ) If ( boldsymbol{x} ) and ( boldsymbol{y} ) are
measured in cm then velocity of wave is
A. ( 64 mathrm{cm} / mathrm{s} ) along ( -x ) direction
B. ( 32 c m / s ) along ( -x ) direction
c. ( 32 c m / s ) along ( +x ) direction
D. ( 64 mathrm{cm} / mathrm{s} ) along ( +x ) direction
11
493State whether the given statement is True or False:

The ripples in water waves are created by the oscillatory movement of water
particles.
A. True
B. False

11
494If the frequency and amplitude of a transverse wave on a string are both doubled, then the amount of energy
transmitted through the string is
A. doubled
B. become 4 time
c. becomes 16 times
D. becomes 32 times
11
495What should a piano tuner do to correct the sound of a string that is flat, that is, it plays at a lower pitch than it should?
A. Tighten the string to make the fundamental frequency higher
B. Tighten the string to make the fundamental frequency lower
c. Loosen the string to make the fundamental frequency higher
D. Loosen the string to make the fundamental frequency lower
E. Find a harmonic closer to the desired pitch
11
496Three waves of equal frequency having amplitudes ( 10 m m, 4 m m ) and ( 7 m m ) arrive at a given point with successive phase difference ( frac{pi}{2} . ) The amplitude of the resulting wave (in ( mathrm{mm} ) ) is given by:
A . 7
B. 6
c. 5
D. 4
11
497The equation of sound wave is ( y= ) ( 0.0015 sin (62.4 x+316 t) . ) Find the
wavelength of this wave:
A. 0.2 unit
B. 0.1 unit
c. 0.3 unit
D. none of these
11
498Thickness of very thin films can be found by the technique of
A. Dispersion
B. Interference
c. polarization
D. Diffraction
11
499The equation of the standing wave in a string clamped at both ends, vibrating in its third harmonic is given by ( boldsymbol{y}=mathbf{0 . 4} sin (mathbf{0 . 3 1 4} boldsymbol{x}) cos (mathbf{6 0 0} boldsymbol{pi} boldsymbol{t}) ) where
( x ) and ( y ) are in ( mathrm{cm} ) and ( t ) in sec.
a) the frequency of vibration is ( 300 H z )
b) the length of the string is ( 30 mathrm{cm} )
c) the nodes are located at ( x= )
( mathbf{0}, mathbf{1 0 c m}, mathbf{3 0 c m} )
A. Only a is true
B. a, b are true
( c . b, c ) are true
D. a, b, care true
11
500The amplitude of simple harmonic motion represented by the displacement equation ( y(c m)=4(sin 5 ) ( pi t+sqrt{2} cos 5 pi t) ) is :
( A cdot 4 mathrm{cm} )
B. ( 4 sqrt{2} mathrm{cm} )
c. ( 4 sqrt{3} mathrm{cm} )
D. ( 4(sqrt{2}+1) ) cm
11
501For the travelling harmonic wave ( boldsymbol{y}(boldsymbol{x}, boldsymbol{t})=2.0 cos 2 pi(10 mathrm{t}-0.0080 mathrm{x}+0.35) )
where ( x ) and ( y ) are in ( c m ) and ( t ) in ( s ) Calculate the phase difference between oscillatory motion of two points separated by a distance of ( x )
A. ( x=4 m, quad Delta phi=6.4 pi r a d )
в. ( 0.5 m, quad Delta phi=0.6 pi ) rad
( begin{array}{ll}text { c. } lambda / 2, & Delta phi=.6 pi r a dend{array} )
D. 3lambda/4, ( quad Delta phi=2.5 pi r a d )
11
502If a wave completes 24 cycles in 0.8 s, then frequency of the wave is
( A cdot 30 mathrm{Hz} )
в. 8 н ( z )
c. 24 нг
D. 12 Hz
11
503A point source emits sound equally in all directions in a non-absorbing
medium. Two points ( P ) and ( Q ) are at
distance of ( 2 m ) and ( 3 m ) respectively from the source. The ratio of the
intensities of the wave at ( P ) and ( Q ) is:
A . 9: 4
B. 2: 3
( c .3: 2 )
D. 4: 9
11
504During propagation of longitudinal plane wave in a medium, two particles separated by a distance equivalent to one wavelength at an instant will be/have
A. In phase, same displacement
B. In phase, different displacement
C. Different phase, same displacement
D. Different phase, different displacement
11
505Two vehicles, each moving with speed ( mathbf{u} )
on the same horizontal straight road,
are approaching each other. Wind blows
along the road with velocity w. One of these vehicles blows a whistle of
frequency ( mathbf{f}_{1} . ) An observer in the other
vehicle hears the frequency of the
whistle to be ( f_{2} . ) The speed of sound in
still air is ( mathrm{V} ). The correct statement(s) is
( (operatorname{are}) )
This question has multiple correct options
A. If the wind blows from the observer to the source, ( f_{2}> )
( f_{1} )
B. If the wind blows from the source to the observer, ( f_{2}> )
( f_{1} )
C. If the wind blows from observer to the source, ( f_{2}<f_{1} )
D. If the wind blows from the source to the observer ( f_{2}< )
( f_{1} )
11
506A wave is travelling in a medium with frequency ( boldsymbol{f}=mathbf{1 0}^{mathbf{1 4}} boldsymbol{H} boldsymbol{z} ) and speed ( boldsymbol{v}= )
( 100 m / s, ) Find out its wavelength?
B. ( 10^{-12} m )
c. ( 10^{10} m )
( mathbf{D} cdot 10^{12} m )
E ( .10^{16} m )
11
507A string is stretched between fixed points separated by ( 75 mathrm{cm} ). It is observed to have resonant frequencies
of ( 420 H z ) and ( 315 H z . ) There are no
other resonant frequencies between these two. Then, the lowest resonant
frequency for this string is
A. ( 10.5 ~ H z )
в. ( 105 mathrm{Hz} )
c. ( 1.05 mathrm{Hz} )
D. ( 1050 mathrm{Hz} )
11
508The isothermal elasticity of a medium
is ( E_{i} ) and the adiabatic elasticity is ( E_{a} )
The velocity of the sound in the medium is proportional to:
A ( cdot sqrt{E_{i}} )
в. ( E_{a} )
( mathrm{c} cdot sqrt{E_{a}} )
D. ( E_{i} )
11
509For superposition of two waves, which
of the following is correct
A. They must have the same frequency and wavelength
B. They must have equal frequencies but may have unequal wavelengths
C. They must have the same wave-length, but may have different frequencies
D. They may have different wavelength and different frequencies
11
510A string is stretched between fixed points separated by ( 75.0 mathrm{cm} ). It is observed to have resonant frequencies
of ( 420 H z ) and ( 315 H z . ) There are no
other resonant frequencies between these two. Then, the lowest resonant
frequency for this string is
( mathbf{A} cdot 105 H z )
в. ( 1.05 mathrm{Hz} )
( mathrm{c} .1050 mathrm{Hz} )
D. ( 10.5 mathrm{Hz} )
11
511A wave completes 20 vibrations in 2.5 s.
Its frequency is
( A cdot 20 H z )
в. 8 н ( z )
c. 200 н ( z )
D. 50 Hz
11
512A standing wave is produced on a string
fixed at one end and free at other. The
length of the string must be an
A ( cdot ) odd integral multiple of ( frac{lambda}{4} )
B. integral multiple of ( frac{lambda}{2} )
c. integral multiple of ( lambda )
D. integral multiple of ( frac{lambda}{4} )
11
513For a longitudinal wave,
A. the disturbance direction is perpendicular to the propagation direction.
B. the disturbance direction is parallel to the propagation direction.
C. the disturbance direction is independent of the propagation direction.
D. None of these
11
514A progressive wave moves with a velocity of ( 36 m / s ) in a medium with a
frequency of ( 200 H z . ) The phase difference between two particles
separated by a distance of ( 1 mathrm{cm} ) is:
A . 40
B . 20
c.
D. ( frac{pi}{16} )
11
515Two particles are executing ( S . H . M ) of same amplitude and frequency along the same straight line path. They pass each other when going in opposite directions, each time their displacement is half of their amplitude. What is the phase difference between
them?
A ( .5 pi / 6 )
в. ( 2 pi / 3 )
c. ( pi / 3 )
D. ( pi / 6 )
11
516toppr
Q Type your question
the velocity of man with respect to
ground any how remains constant)
Plank is placed on smooth horizontal
surface. The man, while running
whistles with frequency ( f_{0} . ) A detector
(D) placed on plank detects frequency.
The man jumps off with same velocity (w.r.t. to ground) from point ( mathrm{D} ) and slides on the smooth horizontal surface
[Assume coefficient of friction between
man and horizontal is zero]. The speed
of sound in still medium is ( 330 mathrm{m} / mathrm{s} )
Answer following questions on the basis of above situations. Choose the correct
plot between the frequency detected by detector versus position of the man relative to detector:
( A )
B.
( c )
( D )
11
517A sinusoidal wave is travelling along a rope. The oscillator that generates the wave completes 60 vibrations in 30 s. Also a given maximum travels ( 425 mathrm{cm} ) along the rope in 10.0 s. What is the
wavelength of the wave?
A. ( 21.25 mathrm{cm} )
B. 36.32 ( mathrm{cm} )
c. ( 48.26 mathrm{cm} )
D. 42.50 ( mathrm{cm} )
11
518If you set up the seventh harmonic on a string fixed at both ends, how many nodes and antinodes are set up in it.
( A cdot 8,7 )
в. 7,7
c. 8,9
D. 9,8
11
519Two monatomic ideal gases 1 and 2 of
molecular masses ( m_{1} ) and ( m_{2} )
respectively are enclosed in separate containers kept at the same temperature. The ratio of the speed of sound in gas 1 to gas 2 is given by
A. ( frac{m_{1}}{m_{2}} )
B. ( sqrt{frac{m_{1}}{m_{2}}} )
c. ( frac{m_{2}}{m_{1}} )
D. ( sqrt{frac{m_{2}}{m_{1}}} )
11
520At a moment in a progressive wave, the phase of a particle executing ( mathrm{SHM} ) is ( frac{pi}{3} ) Then the place of the particle ( 15 mathrm{cm} ) ahead and at time ( frac{T}{2} ) will be, if the wavelength is ( 60 mathrm{cm} )
A. zero
в. ( frac{pi}{2} )
c. ( frac{5 pi}{6} )
D. ( frac{2 pi}{3} )
11
521When a sound wave goes from one medium to another, the quantity that remains unchanged is
A. Frequency
B. amplitude
c. wavelength
D. speedd
11
522The power of a progressive wave of wave
speed ( mathbf{v} ) is the energy supplied to a medium of length ( v ) in one second :
A. True
B. False
11
523Use the formula ( v=sqrt{frac{gamma P}{rho}} ) to explain
why the speed of sound in air
(a) is independent of pressure,
(b) increases with temperature,
(c) Increases with humidity.
11
524A string fixed at its both ends vibrates
in 5 loops as shown in the figure
the total number of nodes and antinode
are respectively:
A . 5,6
B. 6,5
( c .7 .4 )
D. 4,7
11
525A wave creates disturbance and
transmits matter from one place to
another.
A. True
B. False
11
526Which of the following is not a longitudinal wave?
A. Seismic P-wave
B. Light
c. sound
D. Ultrasound
11
527The distance between any two crests or troughs is ( 0.5 mathrm{m} ) in a travelling wave. Find the wavelength of the wave
A . ( 0.5 mathrm{m} )
B. ( 1 mathrm{m} )
c. ( 0.25 mathrm{m} )
D. 1.5 ( m )
11
528The frequency, wavelength and speed of
a sound wave are related as :
( boldsymbol{v}=operatorname{velocity} ) of ( boldsymbol{w} boldsymbol{a v e}, boldsymbol{u}= )
frequency, ( lambda= )wavelength
This question has multiple correct options
A ( . lambda=v T )
В. ( lambda=v / u )
c. ( u=v / lambda )
D. ( lambda=u v )
( v )
11
529A triangular transverse wave is
propagating in the positive ( X ) -direction
Velocity of ( boldsymbol{P} ) at this instant will be
B. Vertically downward
c. At rest
D. Cannot be determined
11
530If a sine wave of amplitude ( 5 mathrm{cm} ) wavelength ( 3 mathrm{cm} ) and frequency ( 10 mathrm{Hz} ) moves in space, what is its speed
( A cdot 3 m / s )
B. ( 0.3 mathrm{m} / mathrm{s} )
( c cdot 0.6 m / s )
D. ( 0.03 mathrm{m} / mathrm{s} )
11
531Two waves ( boldsymbol{y}_{1}=boldsymbol{A} sin [boldsymbol{k}(boldsymbol{x}-boldsymbol{c} boldsymbol{t})] ) and
( boldsymbol{y}_{2}=boldsymbol{A} sin [boldsymbol{k}(boldsymbol{x}+boldsymbol{c} boldsymbol{t})] ) are superimposed
on a string. The distance between adjacent nodes is
11
532Vibrations of period 0.25 s propagate along a straight line at a velocity of 48 ( mathrm{cm} / mathrm{s} . ) One second after the emergence of vibrations at the initial point, displacement of the point, ( 47 mathrm{cm} ) from it is found to be ( 3 mathrm{cm} ). Then,
A. amplitude of vibrations is 6 cm
B. amplitude of vibrations is ( 3 sqrt{2} c m ).
c. amplitude of vibrations is 3 ( mathrm{cm} )
D. None of the above
11
533Two identical flutes produce fundamental notes of frequency ( 300 H z )
at ( 27^{circ} mathrm{C} ). If the temperature in the air in
one of the flutes is increased to ( 31^{circ} C )
the number of beats heard per second will be:
A . 3
B. 2
( c cdot 1 )
D.
11
534How long after the beginning of motion is the displacement of a harmonically oscillating particle equal to one half its
amplitude if the period is ( 24 s ) and
particle starts from rest
A . ( 12 s )
B . 2 s
( c cdot 4 s )
D. ( 6 s )
11
535Source ( S ) emits microwaves with a
constant amplitude. The microwave hit a metal screen ( P ) and are reflected. stationary wave is formed between ( S )
and ( P . ) The wavelength of the microwaves is much smaller than the
distance between ( S ) and ( P )
A detector ( Q ) is moved at a slow,
constant speed from ( S ) to ( P )
What happens to the amplitude of the signal detected by ( Q> )
A. decreases steadily
B. increases and decreases steadily
c. increases steadily
D. remains constant
11
536A string vibrates in 4 segments to a frequency of 400 Hz. What frequency will cause it to vibrate into 7 segments?
A. ( 700 H z )
в. ( 500 H z )
c. ( 400 mathrm{Hz} )
D. ( 100 H z )
11
537The diagram below shows two sources,
( A ) and ( B, ) vibrating in phase in the same
uniform medium and producing
circular wave fronts.
Which phenomenon occurs at point ( P ? )
A. Destructive interference
B. Constructive interference
C . Refletion
D. Refraction
11
538The speed of propagation of a wave in a medium is ( 300 mathrm{m} / mathrm{s} ). The equation of
motion of point at ( x=0 ) is given by ( y= ) ( 0.04 sin 600 pi t(text { metre }) . ) The
displacement of a point ( x=75 mathrm{cm} ) at ( t= ) ( 0.01 mathrm{s} ) is
A . ( 0.02 mathrm{m} )
B. 0.04 ( m )
c. zero
D. ( 0.028 mathrm{m} )
11
539A transverse sinusoidal wave moves
along a string in the positive x-direction at a speed of ( 10 mathrm{cm} / mathrm{s} ). The wavelength
of the wave is ( 0.5 m ) and its amplitude is
10cm. At a particular time ( t ), the snap shot of the wave is shown in figure.
The velocity of point P when its
displacement is ( 5 c m ) is
A ( cdot frac{sqrt{3} pi}{50} hat{j} m / s )
B. ( -frac{sqrt{3} pi}{50} hat{j} m / s )
c. ( frac{sqrt{3} pi}{50} hat{i} m / s )
D. ( -frac{sqrt{3} pi}{50} hat{i} m / s )
11
540In a wave motion ( y=alpha sin (K x-omega t) )
the equation represents:
A . electric field
B. magnetic field
c. displacement field
D. pressure wave
11
541Two sources ( A ) and ( B ) are sounding notes of frequency ( 660 mathrm{Hz} ) A listener moves from ( A ) to ( B ) with a constant
velocity ( u . ) If the speed of sound is
( 330 mathrm{m} / mathrm{s} ) what must be the value of ( u )
so that he hears 8 beats per second?
A ( .2 .8 mathrm{m} / mathrm{s} )
в. ( 2 m / s )
c. ( 3.0 mathrm{m} / mathrm{s} )
D. ( 3.5 mathrm{m} / mathrm{s} )
11
542When two progressive waves ( boldsymbol{y}_{1}= )
( 4 sin (2 x-6 t) ) and ( y_{2}=3 sin (2 x- )
( left.6 t-frac{pi}{2}right) ) are superimposed, the
amplitude of the resultant wave is
11
543A tuning fork vibrating with a sonometer wire of length ( 20 mathrm{cm} ) produces 5 beats per second. The beat frequency does not change if the length of the wire is changed to ( 21 mathrm{cm} . ) The frequency of the tuning fork must be:
A ( .200 mathrm{Hz} )
в. 210 Нг
c. ( 205 ~ H z )
D. 215 Н
11
544A transverse wave of amplitude ( 0.01 m )
and frequency ( 500 H z ) is travelling
along a stretched string with a speed of ( 200 m / s . ) Find the displacement of a particle at a distance of ( 0.7 mathrm{m} ) from the
origin after ( 0.01 s . ) Also find the phase difference between the point where
wave reaches from the origin
11
545A wave travelling along positive x-axis
is given by ( =A sin (omega t-k x) . ) If it is
reflected from a rigid boundary such that ( 80 % ) amplitude is reflected, then equation of reflected wave is
( mathbf{A} cdot y=A sin (omega t+0.8 k x) )
B . ( y=-0.8 A sin (omega t+k x) )
c. ( y=A sin (omega t+k x) )
D ( cdot y=0.8 A sin (omega t+k x) )
11
546Two coherent sources have intensities
in the ratio ( 25: 16 . ) Find the ratio of
intensities of maxima to minima?
11
547A string oscillates according to the
equation ( boldsymbol{y}^{prime}= )
( (0.50 c m) sin left[left(frac{pi}{3} c m^{-1}right) xright] cos left[left(40 pi s^{-1}right)right. )
What is the speed of the two waves(identical except for direction of travel) whose superposition gives this oscillation?
11
548The displacement ( y ) in centimeters is
given in terms of time ( t ) in second by the
equation: ( y=3 sin 3.14 t+4 cos 3.14 t )
then the amplitude of SHM is
( A cdot 3 mathrm{cm} )
B. ( 4 mathrm{cm} )
( c cdot 5 mathrm{cm} )
D. ( 7 mathrm{cm} )
11
549A source of sound producing wavelength ( 50 mathrm{cm} ) is moving away from a stationary observer with ( frac{1}{5}^{t h} ) speed of sound. Then what is the wavelength of sound heard by the observer?
( mathbf{A} cdot 55 mathrm{cm} )
B. ( 40 mathrm{cm} )
( c .60 mathrm{cm} )
D. ( 70 mathrm{cm} )
11
550For a travelling wave match the
following two columns.
11
551In a string the speed of wave is ( 10 mathrm{m} / mathrm{s} )
and its frequency is 100 Hz. The value of
the phase difference at a distance 2.5
cm will be :
( mathbf{A} cdot pi / 2 )
в. ( pi / 8 )
c. ( 3 pi / 2 )
D. ( 4 pi )
11
552Of the following, the equation of plane progressive wave is:
A. ( y=r sin omega t )
в. ( y=r sin (omega t-k x) )
c. ( y=frac{a}{sqrt{r}} sin (omega t-k x) )
D. ( y=frac{a}{r} sin (omega t-k t) )
11
553In what time after its motion begins, will a particle oscillating according to
the equation ( x=5 c o s 0.2 pi t ) move from
the mean position to maximum displacement position?
11
554What is the frequency of a wave if 3
waves are produced in half second?
( mathbf{A} .8 H z )
в. ( 9 H z )
( mathrm{c} .5 mathrm{Hz} )
D. ( 6 H z )
11
555All waves can be classified into two
categories which are
A. Sound waves and electromagnetic waves
B. Transverse waves and electromagnetic waves
C. Longitudinal waves and electromagnetic waves
D. Transverse waves and longitudinal waves
11
556A particle of mass ( 10 g ) is placed in potential field, given by ( V=left(50 x^{2}+right. )
100) erg/g. What will be frequency of
oscillation of particle?
11
557Two waves in the same medium are
represented by ( y-t ) curves in the
figure shown. Find the ratio of their
average intensities?
A ( cdot frac{25}{16} )
B. ( frac{23}{16} )
c. ( frac{21}{16} )
D. ( frac{27}{16} )
11
558A certain transverse wave is described
by ( boldsymbol{y}(boldsymbol{x}, boldsymbol{t})= )
( (6.50 m m) cos 2 pileft(frac{x}{28.0 c m}-frac{t}{0.0360}right. )
The wave’s amplitude is ( 6.50 times 10^{-x} m )
Find the value of ( x )
11
559A tuning fork of unknown frequency makes three beats per second with a
standard fork of frequency 384 Hz. The beat frequency decreases when a small piece of wax is put on a prong of the first fork. What is the frequency of this fork ? ( (text { in } mathrm{Hz}) )
11
560A transverse wave is given by ( A sin (t x) )
where ( A ) and ( t ) are constants. The ratio
of wave velocity to maximum particle velocity is
A. ( A )
B. ( frac{1}{A} )
c.
D. none of the above
11
561If Youngs modulus of the material of a rod is ( 2 times 10^{11} mathrm{Nm}^{-2} ) and density is
( 8000 mathrm{kg} mathrm{m}^{-3}, ) the time taken by a sound wave to traverse ( 1 mathrm{m} ) along the rod is
A. ( 1.11 times 10^{-4} s )
В. ( 3 times 10^{-4} s )
c. ( 2 times 10^{-4} s )
D. ( 1 times 10^{-4} s )
11
562Which of the following statement is incorrect for a stationary wave?
A. Every particle has fixed amplitude which is different from the amplitude of its nearest particle
B. All the particles cross their mean position at the same time
C. All the particles are oscillating with same amplitude.
D. There is no net transfer of energy across any plane
11
563A horizontal stretched string fixed at two ends, is vibrating in its fifth harmonic according to the equation
( boldsymbol{y}(boldsymbol{x}, boldsymbol{t})= )
( 0.01 m sin left[left(62.8 m^{-1}right) xright] cos left[left(628 s^{-1}right) tright] )
Assuming ( pi=3.14, ) the correct statement(s) is/are

This question has multiple correct options
A. The number of nodes is 5
B. the length of the string is 0.25 m
c. The maximum displacement of the midpoint of the string, fom its equilibrium position is ( 0.01 m ).
D. The fundamental frequency is ( 100 H z )

11
564A particle is vibrating simple harmonically with an amplitude ( a ). The
displacement of the particle when its energy is half kinetic and half potential.
A ( cdot a )
B. ( frac{a}{sqrt{2}} )
( c cdot a )
D. zero
11
565The path difference between the two
waves
( boldsymbol{y}_{1}=boldsymbol{a}_{1} sin left(boldsymbol{omega} boldsymbol{t}-frac{boldsymbol{2} boldsymbol{pi} mathbf{x}}{boldsymbol{lambda}}right) ) and
( boldsymbol{y}_{2}=boldsymbol{a}_{2} cos left(boldsymbol{omega} boldsymbol{t}-frac{boldsymbol{2} boldsymbol{pi} mathbf{x}}{boldsymbol{lambda}}+boldsymbol{theta}right) )
( A cdot frac{lambda}{2 pi} )
в. ( frac{lambda}{2 pi}left(theta+frac{pi}{2}right) )
c. ( frac{lambda}{2 pi}left(theta-frac{pi}{2}right) )
D. ( frac{2 pi}{lambda} )
11
566A wave is represented by the equation ( boldsymbol{y}=boldsymbol{A} sin (mathbf{1 0} boldsymbol{pi} boldsymbol{x}+mathbf{1 5} boldsymbol{pi} boldsymbol{t}+boldsymbol{pi} / mathbf{3}) ) where ( boldsymbol{x} )
is in meters and ( t ) is in seconds. The
expression represents:
A. a wave travelling in the positive ( x ) -direction with a velocity ( 1.5 mathrm{m} / mathrm{s} )
B. a wave travelling in the negative ( x ) -direction with a velocity ( 1.5 mathrm{m} / mathrm{s} )
c. a wave travelling in the negative ( x ) -direction having a wavelength ( 0.2 m )
D. a wave travelling in the positive ( x ) -direction having a wavelength ( 0.2 m )
11
567A tuning fork vibrating with a sonometer having ( 20 mathrm{cm} ) wire produces 5 beats/s. The beat frequency does not
change, if the length of the wire is changed to ( 22 mathrm{cm} . ) The frequency of the tuning fork (in Hz) must be
A . 200
B. 210
( c cdot 105 )
D. 125
11
568A sitar wire vibrates with frequency of 330 vibrations per second. If its length is increased three times and tension is
increased four times then the frequency of the wire will be
A . ( 110 mathrm{Hz} )
в. 220 Н
c. ( 330 H z )
D. ( 440 mathrm{Hz} )
11
569Two waves represented by ( y_{1}= )
( 10 sin (2000 pi t) ) and ( y_{2}= )
( 10 sin (2000 pi t+pi / 2) ) are
superimposed at any point at a particular instant. The resultant amplitude is?
A. 10 units
B. 20 units
c. 14.1 units
D. zero
11
570The transverse displacement ( y(x, t) ) of ( a )
wave on a string is given by ( y(x, t)= ) ( e^{left(a x^{2}+b t^{2}+2 sqrt{a b} x tright)} . ) This represents a
A ( cdot ) wave moving in -x direction with speed ( sqrt{frac{b}{a}} )
B. standing wave of frequency ( sqrt{b} )
C standing wave of frequency ( sqrt{frac{1}{sqrt{b}}} )
D. wave moving in + x direction with ( sqrt{frac{a}{b}} )
11
571Doppler’s effect in sound in addition to
the relative velocity between source and
observer also depends on whether source and observer also depend on whether source or observer or both are
moving. Doppler effect in light depends only on the relative velocity of source and observer, the reason for this is:
A. Einstein’s mass-energy relation.
B. Photoelectric effect.
c. the velocity of the observer with respect to the light velocity is negligible.
D. none of these
11
572If the density of materials of two strings of same length, tension and area of cross-section are 2 kgm ( ^{-3} ) and
( 4 k g m^{-3} ) respectively then the ratio of their frequencies will be
A. ( 1: sqrt{2} )
2 ( : sqrt{2} cdot sqrt{2} )
B . 2: 1
c. 1: 2
D. ( sqrt{2}: 1 )
11
573In a stationary wave that from as a result of reflection of waves from an
obstacle, the ratio of the amplitude at an antinode to the amplitude at node is
6. What percentage of energy is transmitted?
11
574The wave number of energy emitted when electron jumps from fourth orbit to seconds orbit in hydrohen in ( 20,497 mathrm{cm}^{-1} . ) The wave number of
energy for the same transition in ( boldsymbol{H} boldsymbol{e}^{+} )
is
A ( .5,099 mathrm{cm}^{-1} )
B . ( 20,497 mathrm{cm}^{-1} )
c. ( 40,994 mathrm{cm}^{-1} )
D. ( 81,988 mathrm{cm}^{-1} )
11
575Water waves coming into shore arrive
every 4 seconds. The waves at ( 2.0 m / s )
How long are the waves?
A . ( 4.0 mathrm{m} )
в. ( 8.0 m )
( c .2 .0 m )
D. ( 0.50 m )
E . ( 16.0 m )
11
576A tuning fork of frequency ( 340 H z ) is vibrated just above the tube of ( 120 mathrm{cm} ) height. Water is poured slowly in the tube. What is the minimum height of water necessary for the resonance?
speed of sound in air ( =340 m / s )
( mathbf{A} cdot 45 mathrm{cm} )
B. ( 30 mathrm{cm} )
c. ( 40 mathrm{cm} )
D. ( 25 mathrm{cm} )
11
577When resonance of two sound waves
occurs, resultant wave have:
A. a loud sound
B. absorption of light waves
c. a dark color
D. transmission of light waves
E. a light color
11
578The figure shown a triangular pulse on rope at ( t=0 . ) It is approaching a fixed end at ( 2 mathrm{cm} / mathrm{s} ) Draw the pulse at ( t=2 )
( sec )
11
579Two waves with same amplitude, frequency and phase are travelling along ( X ) and ( Y ) axis to meet at the origin forming stationary waves
A . True
B. False
11
580A wave of length ( 2 m ) is superposed on
its reflected wave to form a stationary wave. A node is located at ( x=3 m ) The
next node will be located at ( x= )
A. ( 4 m )
B. ( 3.75 m )
( c .3 .50 m )
D. ( 3.25 m )
11
581A transverse wave passes through a string with the equation ( boldsymbol{y}= )
( 10 sin pi(0.02 x-2 t) ) where ( x ) is in
metres and ( t ) in seconds. The maximum
velocity of the particle in wave motion is
A ( cdot 63 m s^{-1} )
B. ( 78 mathrm{ms}^{-1} )
c. ( 100 m s^{-1} )
D. ( 121 mathrm{ms}^{-1} )
11
582Two small boats are ( 10 m ) apart on a
lake. Each pops up and down with a period of 4.0 seconds due to wave motion on the surface of the water.
When one boat is at its highest point. the other boat is at its lowest point. Both boats are always within a single cycle of the waves. The speed of the waves is
A ( .2 .5 mathrm{m} / mathrm{s} )
B. ( 5.0 mathrm{m} / mathrm{s} )
c. ( 14 mathrm{m} / mathrm{s} )
D. ( 40 mathrm{m} / mathrm{s} )
11
583The frequency of a tuning fork ( A ) is ( 2 % )
greater than that of a standard fork ‘ ( K ).
The frequency of another tuning fork ‘ ( boldsymbol{B}^{prime} )
is ( 3 % ) less than ( ^{prime} K^{prime} ). When ( ^{prime} A^{prime} ) and ( ^{circ} B^{prime} )
are vibrated together 6 beats per second are heard. The frequencies of ‘ ( boldsymbol{A}^{prime} )
and ‘ ( boldsymbol{B} ) ‘ are:
В. 132.4Нz,116.4Нz
c. ( 142.4 mathrm{Hz}_{2}, 16.4 mathrm{Hz} )
D. 152.4Hz,116.4Hz
11
584The equation ( boldsymbol{y}=mathbf{4}+mathbf{2} sin (mathbf{6} boldsymbol{t}-mathbf{3} boldsymbol{x}) )
represents a wave motion with amplitude of
A. 6 units
B. 2units
c. 20 units
D. 8 units
11
585An ultrasonic source emits sound of frequency ( 220 mathrm{kHz} ) in air. If this sound meets a water surface, what is the
wavelength of the transmitted sound? (At the atmospheric temperature, speed of sound in air ( = )
( 352 m s^{-1} )andinwater( =1.496 m s^{-1} )
A ( .5 .8 times 10^{-3} mathrm{m} )
В. ( 6.8 times 10^{-3} mathrm{m} )
c. ( 7.8 times 10^{-3} m )
D. ( 8.8 times 10^{-3} mathrm{m} )
11
586Air column of ( 20 mathrm{cm} ) length in a resonance tube resonates with a
certain tuning fork when sounded at its upper open end. The lower end of the tube is closed and adjustable by
changing the quantity of mercury filled inside the tube. The temperature of the
air is ( 27^{circ} mathrm{C} ). The change in length of the
air column required, if the temperature
falls to ( 7^{circ} mathrm{C} ) and the same tuning fork is again sounded at the upper open end is
( mathbf{A} cdot 1 mathrm{mm} )
B. 7 mm
( c cdot 5 m m )
D. ( 13 mathrm{mm} )
11
587A sound wave of frequency 500 Hz covers a distance of ( 1000 mathrm{m} ) in ( 5 mathrm{s} )
between points ( x ) and ( y . ) Then the number of waves between ( x ) and ( y ) are
A. 5000
B. 2500
( c cdot 100 )
D. 500
11
588A string of length ( 0.4 mathrm{m} & operatorname{mass} 10^{2} mathrm{kg} )
is tightly clamped at its ends. The tension in the string is 1.6 N. Identical wave pulses are produced at one end at equal intervals of time, ( Delta ) t. The minimum value of ( Delta t ) which allows
constructive interference between
successive pulses is:
A . ( 0.05 mathrm{s} )
B. 0.10 s
c. ( 0.20 mathrm{s} )
D. 0.40 s
11
589A train, blowing a whistle of frequency ( f ) is standing in the railway yard. A person is running towards the engine.
The frequency of the sound of the whistle as heard by the personn will be
A. greater than ( f )
B. less than ( f )
c. equal to ( f )
D. greater or less than ( f ) depending on the speed of the train
11
590The speed at which a source of sound
should move so that a stationary observer finds the apparent frequency equal to half of the original frequency
A ( cdot frac{V}{2} )
B. 2
c. ( frac{V}{4} )
D. ( V )
11
591Calculate the maximum wavelength of Balmer series in the hydrogen spectrum. Calculate the corresponding wave number.
( boldsymbol{R}=mathbf{1 . 0 9 7} times mathbf{1 0}^{mathbf{7}} boldsymbol{m}^{-mathbf{1}} )
11
592For a wave displacement amplitude is
( 10^{-8} m, ) density for air ( 1.3 k g . m^{-3} )
velocity in air ( 340 m^{-1} ) and frequency is
( 2000 H z . ) The average intensity of wave
is
A ( cdot 5.3 times 10^{-4} mathrm{Wm}^{-2} )
B. ( 5.3 times 10^{-5} mathrm{Wm}^{-2} )
c. ( 5.3 times 10^{-8} mathrm{Wm}^{-2} )
D. ( 5.3 times 10^{-6} mathrm{Wm}^{-2} )
11
593One similarity between sound and light
waves is that
A. Both can propagate in vacuum
B. Both have same speedd
c. Both can show polarization
D. Both can show interference
11
594Two sound waves travelling in the same
direction are represented by equations ( boldsymbol{Y}_{1}=boldsymbol{A}_{1} operatorname{Sin} mathbf{5 0 4} boldsymbol{pi} boldsymbol{t} ; boldsymbol{Y}_{2}= )
( A_{2} ) Sin ( 512 pi t . ) These two sound waves
superpose to produce beats. The intensity of sound changes from minimum to maximum in a time of
A ( .1 / 2 s )
B. 1/4s
c. ( 1 / 8 ) s
D. ( 1 / 16 ) s
11
595A wave is moving towards positive ( x )
axis as shown in figure. Then the point(s) at which acceleration and velocity of particle are parallel to each
other
( A cdot A, D )
B. В, C
( mathbf{c} )
D. A.
11
596Which type of wave is produce in a
resonance tube?
A. longitudinal
B. transverse
c. transverse stationary
D. longitudinal stationary
11
597A harmonic oscillator vibrates with
amplitude of ( 4 mathrm{cm} ) and performs 150 oscillations in one minute. If the initial
phase is 450 and it starts moving away from the equation of motion is
A ( cdot 0.04 sin left(5 pi t+frac{pi}{4}right) )
B. ( 0.04 sin left(5 pi t-frac{pi}{4}right) )
c. ( 0.04 sin left(4 pi t+frac{pi}{4}right) )
D. ( 0.04 sin left(4 pi t-frac{pi}{4}right) )
11
598An air column in a pipe, which is closed at one end, will be in resonance with a
vibrating tuning fork of frequency ( 264 H z ) if the length of the column in
( c m ) is:
A. 31.25
B. 62.50
c. 93.75
D. 125
11
599Consider three waves represented by
( boldsymbol{y}_{1}=boldsymbol{3} sin (boldsymbol{k} boldsymbol{x}-boldsymbol{omega} boldsymbol{t}) )
( boldsymbol{y}_{2}=boldsymbol{3} sin left(boldsymbol{k} boldsymbol{x}-boldsymbol{omega} boldsymbol{t}+frac{2 pi}{3}right) )
( boldsymbol{y}_{3}=boldsymbol{3} sin left(boldsymbol{k} boldsymbol{x}-boldsymbol{omega} boldsymbol{t}+frac{4 pi}{3}right) )
What is the amplitude or resultant of
waves at ( x=0 ? )
( A cdot O )
B. 9
( c cdot 6 )
( D )
11
600A progressive wave of wavelength ( 5 mathrm{cm} ) moves along ( +mathrm{X} ) axis. What is the phase difference between two points on the wave separated by a distance of ( 3 mathrm{cm} ) at
any instant
A . ( 3 pi / 5 )
в. ( 6 pi / 5 )
c. ( 2 pi / 5 )
D. ( 7 pi / 5 )
11
601The moon is at a distance of ( 4 times 10^{8} m )
from the earth. What is the nature of
radar signal transmitted from earth?
A. Remain fixed
B. Vibrate to and fro about their mean position
c. Move along the wave
D. change their positions permanently
11
602An object of mass ( 0.2 k g ) executes SHM along the ( x ) -axis with frequency of ( (25 / pi) ) Hz. At the point ( x=0.04 m ) the
object has ( mathrm{KE} mathbf{0 . 5} boldsymbol{J} ) and PE ( mathbf{4} boldsymbol{J} ). The
amplitude of oscillation is
11
603When a sound wave of wavelength ( lambda ) is propagating in a medium the maximum velocity of the particle is equal to wave velocity. The amplitude of the wave is
( A cdot lambda )
B. ( frac{lambda}{2} )
( c cdot frac{lambda}{2 pi} )
D. ( frac{lambda}{4 pi} )
11
604A clamped string is oscillating in nth
harmonic, then
This question has multiple correct options
A . total energy of oscillations will be ( n^{2} ) times that of
fundamental frequency
B. total energy of oscillations will be ( (n-1)^{2} ) times that
of fundamental frequency
C . average kinetic energy of the string over a complete oscillations is half of the total energy of the string
D. none of these
11
605wavelength:11
606A Sound wave with an amplitude of ( 3 c m )
starts moving towards right from origin
and gets reflected at a rigid wall after a
second. If the velocity of the wave is
( 340 m s^{-1} ) and it has a wavelength of ( 2 m )
the equations of incident and reflected
waves are
A ( cdot y=3 times 10^{-2} sin pi(340 t-x), y=-3 x )
( 10^{-2} sin pi(340 t+x) ) towards left
B . ( y=4 times 10^{-2} sin pi(340 t+x), y=-4 times )
( 10^{-2} sin pi(340 t+x) ) towards left
C . ( y=5 times 10^{-2} sin pi(340 t-x), y=-5 times )
( 10^{-2} sin pi(340 t-x) ) towards left
D . ( y=6 times 10^{-2} sin pi(340 t-x), y=-6 times )
[
10^{-2} sin pi(340 t+x) text { towards left }
]
11
607A tuning fork produces 4 beats per second with another tuning fork of
frequency 256 Hz. The first one is now loaded with a little wax and the beat
frequency is found to increase to 6 per second. What was the original frequency of the first tuning fork. (in Hz)
11
608The maximum potential energy / length increases with:
A. Amplitude
B. wavelength
c. Frequency
D. Velocity
11
609Sound waves get reflected from:
A. plane surfaces
B. spherical surfaces
( c . ) hard surfaces
D. all of these
11
610The average power transmitted through a given point on a string with a sine wave is 0.40 watt, when the amplitude of the wave is ( 2 mathrm{mm} ). What average
power will be transmitted through this point its amplitude is increased to 4
( mathrm{mm} )
A. 0.40 watt
B. 0.80 watt
c. 1.2 watt
D. 1.6 watt
11
611A plane progressive wave is given by
( boldsymbol{y}=2 cos 6.284(330 t-x) . ) What is
period of the wave?
( ^{A} cdot frac{1}{33^{0}} )
В. ( 2 pi times 330 s )
c. ( (2 pi times 330)^{-1} ) s
D. ( frac{6.284}{330} )
11
612The wavelength of the pulse when it reaches the other end of the rope is
A. ( sqrt{3} lambda_{0} )
B. ( sqrt{frac{3}{2}} lambda_{0} )
( c cdot lambda_{0} )
D. ( frac{lambda_{0}}{2} )
11
613A pipe’s lower end is immersed in water such that the length of air column from
the top open end has a certain length
( 25 mathrm{cm} . ) The speed of sound in air is
( 350 m / s . ) The air column is found to
resonate with a tuning fork of frequency
( 1750 H z . ) By what minimum distance
should the pipe be raised in order to make the air column resonate again
with the same tuning fork?
( mathbf{A} cdot 7 mathrm{cm} )
B. ( 5 mathrm{cm} )
c. ( 35 mathrm{cm} )
D. ( 10 mathrm{cm} )
11
614A line source emits a cylindrical expanding wave. If the medium absorbs no energy then the amplitude will vary with distance ( r ) from the source as
proportional to
A ( cdot r^{-1} )
B . ( r^{-2} )
( c cdot r^{-1 / 2} )
( mathbf{D} cdot r^{1 / 2} )
11
615A plane electromagnetic wave propagating in ( x(-) ) direction as a wave function (in Sl units) is given as
( mathbf{Phi}(x, t)=10^{3} sin pileft(3 times 10^{6} x-9 xright. )
( mathbf{1 0}^{mathbf{1 4}} boldsymbol{t} )
The speed of the wave is
A. ( 3 times 10^{6} ) m / ( s )
В. ( 3 times 10^{7} mathrm{m} / mathrm{s} )
( mathrm{c} cdot 3 times 10^{8} mathrm{m} / mathrm{s} )
D. ( 9 times 10^{14} mathrm{m} / mathrm{s} )
11
616angular frequency ( (omega) )
( A )
( B )
( c )
( D )
11
617A ratio station transmists musical
programme at ( 220 mathrm{m} ) wavelength and ( 1200 mathrm{Hz} ) frequency. Calculate the velocity of radio waves.
A. ( 346 mathrm{km} / mathrm{sec} )
B. 264 km/sec
c. ( 442 mathrm{km} / mathrm{sec} )
D. ( 468 mathrm{km} / mathrm{sec} )
11
618A uniform string of length ( l ) is fixed at both ends such that tension ( T ) is
produced in it. The string is excited to vibrate with maximum displacement
amplitude ( a_{o} . ) The maximum kinetic
energy of the string for its fundamental tone is given as ( frac{a_{o}^{2} pi^{2} T}{x l} . ) Find ( x )
11
619Find the phase difference between a
particle at ( 1^{s t} ) crest and a particle at ( 4^{t h} )
crest.
11
620Potential energy of a string depends on
A. Wave velocity
B. Amplitude of the wave
c. Extent of stretching of the string
D. None of the above
11
621Waves inside a gas are
A. Longitudinal
B. Transverse
C. Partly longitudinal, partly transverse
D. None of these
11
622How much intense is ( 80 d B ) sound in
comparison to ( 40 d B ? )
A ( cdot 10^{4} )
B . ( 10^{2} )
( c cdot 2 )
D.
11
623A long string under tension of ( 100 N ) has one end at ( x=0 . ) A sinusoidal wave
is generated at ( x=0 ) whose equation is
given by
( boldsymbol{y}= )
( (0.01 c m) sin left[left(frac{pi x}{10} mright)-50 pi t(s e c)right] )
Sketch the shape of the string at ( t= ) ( frac{1}{50} s e c )
11
624Both the strings shown in the figure are
made of same material and have the
same cross-section. The pulleys are
light. The wave speed of a transverse
wave in the string ( A B ) is ( v_{1} ) and in ( C D ) it
is ( boldsymbol{v}_{2} ) The ( boldsymbol{v}_{1} / boldsymbol{v}_{2} ) is
( A )
B. 2
( c cdot sqrt{2} )
D. ( frac{1}{sqrt{2}} )
11
625As wave travels, intensity
A. increases
B. remains same
c. decreases
D. becomes negative
11
626A source of sound ( A ) emit waves of
frequency ( 1800 mathrm{Hz} ) is falling towards ground with a terminal speed ( v . ) The observer ( B ) on the ground directly beneath the source receives waves of
frequency ( 2150 H z ). The source ( A ) receives waves, reflected from ground,
of frequency nearly:
(Speed of sound ( =343 mathrm{m} / mathrm{s} ) )
A. ( 2150 H z )
в. ( 2500 H z )
с. ( 1800 H z )
D. 2400H ( z )
11
627For a string clamped at both its ends, which of the following wave equation is/are valid for a stationary wave set up in it? (Origin is at one end of string) This question has multiple correct options
A. ( y=A sin k x . sin omega t )
B. ( y=A cos k x sin omega t )
c. ( y=A sin k x . cos omega t )
D. ( y=A cos k x cos omega t )
11
628A transverse sinusoidal wave is
generated at one end of a long horizontal string by a bar that moves the end up and down through a distance
by ( 2.0 mathrm{cm} . ) The motion of bar is continuous and is repeated regularly
125 times per sec. If the distance between adjacent wave crests is
observed to be ( 15.7 mathrm{cm} ) and the wave
is moving along +ve x-direction, and at ( boldsymbol{t}=mathbf{0}, ) the element of the string at ( boldsymbol{x}=mathbf{0} )
is at mean position ( y=0 ) and is
moving downwards, the equation of the
wave is best described by : ( (u s e pi= )
( mathbf{3 . 1 4}) )
A ( cdot y=(1 c m) sin [(40.0 r a d / m) x-(785 r a d / s) t] )
B . ( y=(2 c m) sin [(40.0 r a d / m) x=(785 r a d / s) t] )
c. ( y=(1 c m) cos [(40.0 r a d / m) x-(785 r a d / s) t] )
D. ( y=(2 c m) cos [(40.0 r a d / m) x-(785 r a d / s) t] )
11
629Calculate the wavelength of the wave as
Shown above:
( A cdot 1 m )
( B cdot 2 m )
( c cdot 3 m )
( D cdot 6 m )
( E cdot 9 m )
11
630Calculate the frequency of beats produced in air when two sources of sound are activated, one emitting a
wavelength of ( 32 c m ) and the other of
( 32.2 mathrm{cm} . ) The speed of sound in air is
( 350 m / s )
( A .3 H z )
в. ( 5 H z )
( mathrm{c} .7 mathrm{Hz} )
D. ( 2 H z )
11
631A policeman blows a whistle with a frequency of ( 500 H z . ) A car approaches
him with a velocity of ( 15 ~ m s^{-1} ). The change in frequency as heard by the driver of the car as he passes the policeman is (Given, speed of sound in air is ( 300 m s^{-1} )
( mathbf{A} cdot 25 H z )
в. ( 50 H z )
c. ( 100 H z )
D. ( 150 H z )
11
632A body executing S.H.M has a maximum
acceleration equal to ( 48 mathrm{m} / mathrm{sec}^{2} ) and maximum velocity equal to ( 12 mathrm{m} / mathrm{sec} )
The amplitude of S.H.M is?
( A cdot 3 m )
B. 3/32 m
c. ( 1024 / 9 mathrm{m} )
D. ( 64 / 9 mathrm{m} )
11
633When two waves of the same amplitude and frequency but having a phase difference of ( phi ) travelling with the same speed in the same direction (positive ( x ) ) meets at a point then
A. their resultant amplitude will be twice that of a single wave but the frequency will be same
B. their resultant amplitude and frequency will both be twice that of a single wave
c. their resultant amplitude will depend on the phase angle while the frequency will be the same
D. the frequency and amplitude of the resultant wave will depend upon the phase angle
11
634If the phase difference between two
component waves of different
amplitudes is ( 2 pi, ) their resultant
amplitude will become
A. sum of the amplitudes
B. difference of the amplitudes
c. product of the amplitudes
D. ratio of their amplitudes
11
635Explain analytically how stationary waves are formed. What are nodes and
antinodes? Show that the distance
between two adjacent nodes or antinodes is ( frac{lambda}{2} )
11
636The picture shows a wave generated in a laboratory. The wavelength of the wave is
A . ( 1.5 mathrm{cm} )
B. ( 1.7 mathrm{cm} )
c. ( 2.0 mathrm{cm} )
D. 2.7 cm
11
637Which of the following functions
represent a wave
A ( cdot(x-v t)^{2} )
B. ( log (x+v t) )
c. ( e^{-(x-v t)^{2}} )
D. ( frac{1}{x+v t} )
11
638A wave of angular frequency ( omega ) propagates so that a certain phase of oscillation moves along x-axis, y-axis
and z-axis with speeds ( c_{1}, c_{2} ) and ( c_{3} )
respectively. The propagation constant ( boldsymbol{k} ) is
A ( cdot frac{omega}{sqrt{c_{1}^{2}+c_{2}^{2}+c_{3}^{2}}}(hat{i}+hat{j}+hat{k}) )
B. ( frac{omega_{hat{i}}}{c_{1}}+frac{omega_{hat{jmath}}}{c_{2}}+frac{omega}{c_{3}} hat{k} )
c. ( (omega hat{i}+omega hat{j}+omega hat{k}) frac{1}{c} )
D. ( frac{omega}{left(c_{1}+c_{2}+c_{3}right)}(hat{i}+hat{j}+hat{k}) )
11
639The equation of sound wave is ( y= ) ( 0.0015 sin (62.4 x+316 t) . ) Find the
wavelength of this wave
A. 0.2 unit
B. 0.1 unit
c. 0.3 unit
D. None of these
11
640A long string under tension of ( 100 N )
has one end at ( x=0 . ) A sinusoidal
wave is generated at ( x=0 ) whose
equation is given by
( boldsymbol{y}= )
( (0.01 c m) sin left[left(frac{pi x}{10} mright)-50 pi t(s e c)right] )
Find the average power transmitted by
the wave.
11
641The phase difference between two
points is ( pi / 3 . ) If the frequency of wave is ( 50 mathrm{Hz}, ) then what is the distance between two points? ( (operatorname{given} v=330 mathrm{m} / mathrm{s}) )
( A cdot 2.2 mathrm{m} )
в. ( 1.1 mathrm{m} )
c. ( 0.6 mathrm{m} )
D. ( 1.7 mathrm{m} )
11
642The equation of an incident wave travelling along +X direction is given by ( boldsymbol{y}=boldsymbol{A} sin (boldsymbol{2} boldsymbol{t}-mathbf{5} boldsymbol{x}) . ) This wave gets
reflected at a rigid boundary. The equation of the reflected wave is
A ( . y=operatorname{Asin}(2 t-5 x) )
B. ( y=operatorname{Asin}(2 t-5 x+pi) )
c. ( y=operatorname{Asin}(2 t+5 x+pi) )
D. ( y=operatorname{Asin}(2 t-5 x+pi / 2) )
11
643At ( t=0, ) a transverse wave pulse in wire is described by the function; ( boldsymbol{y}=frac{boldsymbol{6}}{boldsymbol{x}^{2}+boldsymbol{3}} )
Where ( x ) and ( y ) are in meters. Write the function ( y(x, t) ) that describes this wave if it travelling in the positive ( x ) -direction with a speed of ( 4.50 mathrm{m} / mathrm{s} )
A ( cdot y=frac{12}{left[(x-4.5 t)^{2}+3right]} )
B. ( y=frac{6}{left[(x-4.5 t)^{2}+9right]} )
c. ( y=frac{16}{left[(x-4.5 t)^{2}+3right]} )
D. ( y=frac{6}{left[(x-4.5 t)^{2}+3right]} )
11
644The tones that are separated by three octaves have a frequency ratio of
A . 3: 1
B. 6: 1
c. 8: 1
D. 16: 1
11
645A plane progressive wave travelling in ( -Y ) direction is represented by the equation ( 2 cos (2 pi t+pi y) . ) If this wave was
travelling in ( X ) direction, the frequency of the wave would have been
A. doubled
B. remains same
c. tripled
D. halved
11
646The equation of a standing wave produced on a string fixed at both ends is
( boldsymbol{y}=mathbf{0 . 4} sin [mathbf{0 . 3 1 4 x}] cos [mathbf{6 0 0} boldsymbol{pi} boldsymbol{t}] ) where ( boldsymbol{x} )
and ( y ) are in ( c m ) and ( t ) in seconds. The
smallest possible length of the string is
( mathbf{A} cdot 10 mathrm{cm} )
B. ( 20 mathrm{cm} )
( mathbf{c} .30 mathrm{cm} )
D. ( 40 mathrm{cm} )
11
647The time needed for two complete cycles of vibration is called time period
A. True
B. False
11
648The equation of a wave is given by ( boldsymbol{y}= ) ( 10 sin left[frac{2 pi t}{30}+alpharight] . ) If the displacement is
( 5 c m ) at ( t=0, ) then the total phase at
( t=7.5 s ) will be
A ( cdotleft(frac{2 pi}{3}right) r a d )
В. ( left(frac{2 pi}{5}right) ) rad
c. ( left(frac{pi}{3}right) ) rad
D. ( left(frac{pi}{2}right) ) rad
11
649For the wave shown in figure, the
wavelength of the wave is:
( mathbf{A} cdot 0.4 m )
B. ( 0.2 m )
( mathbf{c} .0 .16 m )
D. ( 0.8 m )
11
650Two stretched wires of same length,
diameter and same material are in
unison. The tension in one is increased
by ( 2 % ) and 2 beats per second are heard What was the frequency of the note produced when they were in unison
A . ( 100 mathrm{Hz} )
в. ( 200 H z )
c. ( 500 H z )
D. ( 400 H z )
11
651Wave pulse on a string shown in the
figure is moving to the right without
changing shape. Consider two particles
at positions ( x_{1}=1.5 m ) and ( x_{2}= )
2.5 ( m . ) Their transverse velocities at the
moment shown in the figure are along
the
A. positive y axis and positive y axis respectively
B. negative y axis and positive y axis respectively
C. positive y axis and negative y axis respectively
D. negative y axis and negative y axis respectively
11
652Which of the following waves does not
travel in vacuum?
A. Seismic waves
B. X-rays
c. Light
D. Radio waves
11
653Phase difference between a particle at a
compression and a particle at the next
rarefaction is
A. zero
в. ( frac{pi}{2} )
( c )
D.
11
654According to Laplace, during the propagation of sound in a gas, an adiabatic change takes place in the medium.
A. True
B. False
11
655Calculate the wavelength of a wave if its frequency is ( 256 mathrm{Hz} ) and and speed of the wave is ( 350 mathrm{m} / mathrm{s} )
( A cdot 89,600 m )
B. 350 ( m )
( c cdot 94 m )
D. ( 1.4 mathrm{m} )
E. ( 0.73 mathrm{m} )
11
656Explain ground wave propagation.11
657The string of a violin emits a note of 205
( mathrm{Hz} ) at its correct tension. The string is tightened slightly and then it produces six beats in 2 seconds with tuning fork of the frequency ( 205 mathrm{Hz} ). The frequency of the note emitted by the taut string is
11
658Two waves of same frequency but amplitudes equal to ( a ) and ( 2 a ) travelling in the same direction superimpose out of phase. The resultant amplitude will be
A. ( sqrt{a^{2}+2 a^{2}} )
B. ( 3 a )
( c cdot 2 a )
( D )
11
659The displacement from the position of
equilibrium of a point ( 4 mathrm{cm} ) from a source of sinusoidal oscillations is half
the amplitude at the moment ( t=frac{T}{6}(T ) is the time period). Assume that the
source was at mean position at ( t=0 )
The wavelength of the running wave is
A ( .0 .96 m )
B. ( 0.48 m )
c. ( 0.24 mathrm{m} )
D. ( 0.12 mathrm{m} )
11
660A tuning fork is in resonance with a sonometer wire. The same tuning fork produces 3 beats in ( 2 s ) when the tension in the wire is increased by ( 2 % ) The frequency of wire before increasing tension is:
A . ( 100 mathrm{Hz} )
в. ( 150 mathrm{Hz} )
c. ( 200 H z )
D. 300 H
11
661In a transverse wave, the particles of the
medium
A. vibrate in a direction perpendicular to the direction of the propagation.
B. vibrate in a direction parallel to the direction of the propagation.
C. move in circle.
D. move in ellipse.
11
662If two waves are represented by ( y_{1}= )
( 2 sin (4 x-300 t) ) and ( y_{2}=sin (4 x- )
( 300 t-0.2) ) then, their superposed wave
will have angular frequency
A. ( 150 / pi )
в. ( 150 pi )
( c .300 )
D. ( 600 pi )
11
663A single wave is called
A. a wave pulse
B. a crest
c. a trough
D. a crest and a trough
11
664The frequency of the 1 st harmonic of a sonometer wire is ( 160 H z ). If the length
of the wire is increased by ( 50 % ) and the tension in the wire is decreased by
( 19 %, ) the frequency of its first overtone
is :
(Assume linear mass density to be constant
A. ( 180 H z )
в. ( 192 mathrm{Hz} )
c. ( 220 H z )
D. 232 Нг
11
665The amplitude of a wave disturbance propagating in the positive y-direction is given by:
( y=frac{1}{1+x^{2}} ) at ( t=0 s a n d y= )
( frac{1}{1+(x-1)^{2}} ) at ( t=2 s, ) then wave
velocity is
A. ( 1 m / s )
в. ( 1.5 m / s )
c. ( 0.5 m / s )
D. ( 2 m / s )
11
666A sinusoidal wave of frequency ( 500 H z )
has a speed of ( 350 m / s ). The phase difference between two displacements at a certain point at times 1 ms apart is
A ( cdot frac{Pi}{4} )
в. ( frac{text { П }}{2} )
( c . Pi )
D. ( frac{3 Pi}{2} )
11
667Is it necessary to have two waves of
equal intensity to study interference pattern? Will there be an effect on clarity if the waves have unequal intensity?
11
668What is the speed of propagation of
transverse wave in the wire?
11
669The number of beats produced per second by two tuning fork when sounded together is ( 4 . ) One of them has a frequency of ( 250 mathrm{Hz} ) and if waxed, number of beats become 6. The
frequency of the other tuning fork is
A . 254 ( mathrm{H} )
B. 252 нz
c. 248 н на
D. 246 нz
11
670Assertion – Sound wave is an example of longitudinal wave. Reason – In longitudinal waves, the
constituents of the medium oscillate
perpendicular to the direction of wave propagation.
A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
c. Assertion is correct but Reason is incorrect
D. Both Assertion and Reason are incorrect
11
671The periodic time of a vibrating body is 0.01 sec. Its frequency will be
A. 1.0 cycles ( / s )
B. 10.0 cycles / s
c. 100.0 cycles ( / ) s
D. 1000.0 cycles ( / s )
11
672The amplitude of two waves are in ratio
( 5: 2 . ) If all other conditions for the two
waves are same, then what is the ratio
of their energy densities?
A . 5: 2
B. 5: 4
( c cdot 4: 5 )
D. 25 : 4
11
673With the propagation of a longitudinal wave through a material medium, the quantities transmitted in the direction of propagation are
A. Energy, momentum and mass
B. Mass and momentum
c. Energy and mass
D. Energy and momentum
11
674The angle between particle velocity and wave velocity in transverse waves is
A . ( pi )
в. ( pi / 2 )
c. ( pi / 4 )
D. zero
11
675Which of the following is incorrect?
A. If the wave is longitudinal, it must be a mechanical wave
B. If the wave is mechanical, it may OR may not be a transverse wave
C. Mechanical waves cannot propagate in vacuum
D. ‘Diffraction’ helps us to distinguish between sound wave and light wave
11
676A series of ocean waves, each ( 5.0 mathrm{m} )
from crest to crest, moving past the observer at a rate of 2 waves per second
What is the velocity of ocean waves?
A. ( 2.5 mathrm{m} / mathrm{s} )
B. ( 5.0 mathrm{m} / mathrm{s} )
( c cdot 8.0 mathrm{m} / mathrm{s} )
D. ( 10.0 mathrm{m} / mathrm{s} )
11
677A broadcasting station transmits waves
of frequency ( 71 times 10^{4} H z ) with a speed
of ( 3 times 10^{8} m / s . ) The wavelength of the
wave is :
A ( .418 .8 m )
в. ( 324.6 m )
c. ( 208.4 m )
D. ( 422.5 mathrm{m} )
11
678A person places his ear at the end of a long steel pipe. He hears two distinct sounds at an interval of 0.5 s when
another person hammers at the other end of the pipe. If the speed of the sound in metal and air are ( 3630 mathrm{ms}^{-1} ) and 330
( mathrm{m} s^{-1} ) respectively, then the distance between the two persons is
A. ( 90.75 mathrm{m} )
в. 181.5 ( mathrm{m} )
c. ( 363 mathrm{m} )
D. 1650 ( mathrm{m} )
11
679Which of the following parameters of a wave undergoes a change when wave is reflected from a boundary?
A. Intensity
B. Phase
c. Speed
D. Frequency
11
680A tuning fork of frequency ( 480 mathrm{Hz} ) produces 10 beats/s when sounded with
a vibrating sonometer string. What must have been the frequency of the string if a slight increase in tension produces fewer beats per second than
before?
A. 460 Н
в. 480 н ( z )
c. 490 н ( z )
D. 470 нz
11
681The displacement of the medium in a
sound wave is given by the equation;
( boldsymbol{y}_{1}=boldsymbol{A} cos (boldsymbol{a} boldsymbol{x}+boldsymbol{b} boldsymbol{t}) ) where ( A, ) a ( & boldsymbol{b} ) are
positive constants. The wave is
reflected by an obstacle situated at ( x= )
0, The intensity of the reflected wave is 0.64 times that of the incident wave.
The wavelength of the incident wave is
Find the value of ( x: ) ( boldsymbol{a} )
11
682For a pulse moving in a heavy string the junctions of the string behaves as a
A. perfectly rigid end
B. free end
c. partially rigid end
D. rigid end
11
683The equation of the standing wave in a string clamped at both ends, vibrating in its third harmonic is given by : ( y= ) ( 0.4 sin (0.314 x) cos (600 pi t) ) where, ( x )
and ( y ) are in ( mathrm{cm} ) and ( t ) in sec.
a) the frequency of vibration is ( 300 H z )
b) the length of the string is ( 30 mathrm{cm} )
c) the nodes are located at ( x= )
( 0,10 c m, 30 c m )
A. a,
в. а,
( c cdot b, c )
D. a,b,
11
684The product of frequency and
wavelength of a sound wave is equal to
its
11
685The amplitude of the wave shown above
is:
( A cdot 8.0 mathrm{m} )
B. 2.0 ( m )
( c cdot 4.0 mathrm{m} )
D. 1.0
E . ( 0.5 mathrm{m} )
11
686A wire stretched between two rigid supports vibrates in its fundamental mode with a frequency of 45 Hz. The
mass of the wire is ( 3.5 times 10^{-2} k g ) and
its linear mass density is ( 4.0 times ) ( 10^{-2} k g m^{-1} . ) What is
(a) the speed of a
transverse wave on the string, and
the tension in the string?
11
687An observer is moving away from a
sound source of frequency ( 100 H_{z} ). If the observer is moving with a velocity of ( 49 m / s e c ) and the speed of the speed of the sound in air is ( 330 m / )sec , then the
apparent frequency is:
A. ( 91 H_{z} )
в. ( 100 H_{z} )
( mathbf{c} cdot 85 H_{z} )
D . ( 149 mathrm{H}_{2} )
11
688Sound waves of wavelength ( lambda ) travelling
with velocity ( v ) in a medium enter into
another medium in which their velocity
is ( 4 v . ) The wavelength in ( 2^{n d} ) medium is :
A ( .4 lambda )
B. ( lambda )
( c cdot lambda / 4 )
D. ( 16 lambda )
11
689In a medium in which, a transverse
progressive wave travelling, the phase difference between the points with a separation of ( 1.25 mathrm{cm} ) is ( pi / 4 . ) If the frequency of wave ( 1000 H z ), the velocity
in the medium is :
A ( cdot 10^{4} m s^{-1} )
В. ( 125 mathrm{ms}^{-1} )
c. ( 100 m s^{-1} )
D. ( 10 mathrm{ms}^{-1} )
11
690A sound is moving towards stationery with ( frac{1}{10} ) the sound. The ratio of apparent to real frequency is
A ( cdot frac{10}{9} )
в. ( left(frac{10}{9}right)^{2} )
c. ( left(frac{11}{10}right)^{2} )
D. ( frac{11}{10} )
11
691Statement-1: When a travelling wave is sent along a particular string by
oscillating one end, the speed of the
wave will increase if we increase the
frequency of oscillations. Statement-2: If a travelling wave sent
along a particular string by oscillating
its one end, it is the wavelength of the
wave that decreases.
A. If both the statements are true and statement- 2 is the correct explanation of statement-
B. If both the statements are true but statement-2 is not the correct explanation of statement-
C. If statement-1 is true and statement-2 is false
D. If statement-1 is false and statement-2 is true
11
692In a certain oscillatory system, the amplitude of motion is ( 5 mathrm{m} ) and the time
period is 4 s. The time taken by the particle for passing between points which are at distance of ( 4 mathrm{m} ) and ( 2 mathrm{m} )
from the centre and on the same side of
it will be
A. 0.30 s
B. 0.32
c. 0.33
D. 0.35
11
693Two particles are executing SHM of same amplitude and frequency along the same straight line path. They pass each other when going in opposite directions, each time their displacement is half of their magnitude.
What is the phase difference between them?
( mathbf{A} cdot pi / 6 )
в. ( 4 pi / 6 )
c. ( pi / 3 )
D. 2pi/6
11
694Two waves of frequencies ( 1 H z ) and
( 3 H z ) are moving in a medium with same velocity. The ratio of intensities at a point where amplitudes of two waves are equal will be
A . 1: 1
B. 1: 4
c. 1: 2
D. 1: 9
11
695For the sustained interference of light,
the necessary condition is that the two sources should
A. have constant phase difference only
B. be narrow
c. be close to each other
D. of same amplitude with constant phase difference
11
696Two sitar strings, ( A ) and ( B ), playing the
note ‘Dha’ are slightly out of tune and
produce beats and frequency 5 Hz.The tension of the string ( B ) is slightly increased and the beat frequency is
found to decrease by ( 3 H z ). If the frequency of ( boldsymbol{A} ) is ( mathbf{4 2 5} boldsymbol{H} boldsymbol{z}, ) the original frequency of ( boldsymbol{B} ) is
A ( .430 H z )
в. 428 Н ( z )
c. ( 422 mathrm{Hz} )
D. ( 420 mathrm{Hz} )
11
697A string is clamped on both ends. Which of the following wave equations is valid for a stationary wave set up on this string? (Origin is at one end of string.)
A. ( y= ) Asinkx sint
B. ( y= )Acoskx sint
c. ( y= ) Acosk ( x ) cost
D. None of the above
11
698The ratio of angular frequency and angular wave number is
A. particle velocity
B. wave velocity
c. energy
D. wavelength per unit oscillation
11
699Two uniform stretched strings ( A ) and ( B ), made of steel, are vibrating under the same tension. If the first overtone of ( A ) is
equal to the second overtone of B and if
the radius of ( A ) is twice that of ( B ), the
ratio of the lengths of the strings is:
A .2: 3
B. 1: 2
c. 1: 3
D. 1: 4
11
700A light pointer fixed to one prong of a tuning fork touched a vertical plate. The fork is set vibrating and plate is allowed
to fall freely. 8 complete oscillations are counted when the plate falls through 10cm. What is the frequency of the
tuning fork?
A. ( 40 sqrt{2} )
в. ( 40 sqrt{3} )
c. ( 20 sqrt{2} )
D. ( 70 sqrt{2} )
11
701The fundamental frequency of vibration of ( 1 mathrm{cm} ) long string is ( 256 mathrm{Hz} ). If the length of the string is reduced to ( frac{1}{4} c m ) keeping the tension unaltered, the new fundamental frequency will be
A ( .256 mathrm{Hz} )
в. 512 Нг
c. ( 1024 mathrm{Hz} )
D. ( 2048 mathrm{Hz} )
11
702If ( n_{1}, n_{2}, n_{3} ) be the frequency of the segments of a stretched string, then the frequency ( n ) of the string itself in terms
of ( n_{1}, n_{2} ) and ( n_{3} ) is
A. ( frac{left(n_{1} n_{2}+n_{2} n_{3}+n_{1} n_{3}right)}{n_{1} n_{2} n_{3}} )
B. ( frac{left(mathrm{n}_{1} mathrm{n}_{2}+mathrm{n}_{3} mathrm{n}_{1}right)}{mathrm{n}_{1} mathrm{n}_{2} mathrm{n}_{3}} )
c. ( frac{mathrm{n}_{1} mathrm{n}_{2} mathrm{n}_{3}}{left(mathrm{n}_{1} mathrm{n}_{2}+mathrm{n}_{3} mathrm{n}_{1}right)} )
D. ( frac{mathrm{n}_{1} mathrm{n}_{2} mathrm{n}_{3}}{left(mathrm{n}_{1} mathrm{n}_{2}+mathrm{n}_{2} mathrm{n}_{3}+mathrm{n}_{3} mathrm{n}_{1}right)} )
11
703Which phenomenon is observed due to the change in speed of wave when it strikes the another medium’s boundary
( ? )
A. Reflection
B. Refraction
c. Polarization
D. Diffraction
E. Interference
11
704Two waves of same amplitude and frequency and travelling in same direction are superimposed each other to give rise to a resultant wave of amplitude ( 2 A )
A. True
B. False
11
705Two organ (open) pipes of lengths 50 ( mathrm{cm} ) and ( 51 mathrm{cm} ) produce 6 beats/s. Then the speed of sound is nearly
( A cdot 300 mathrm{ms}^{-1} )
B. 306 ( mathrm{ms}^{-1} )
c. ( 303 mathrm{ms}^{-1} )
D. 350 ( mathrm{ms}^{-1} )
11
706A harmonically moving transverse wave on a string has a maximum particle velocity and acceleration of ( 3 mathrm{m} / mathrm{s} ) and
( 90 mathrm{m} / mathrm{s}^{2} ) respectively. Velocity of the wave is ( 20 mathrm{m} / mathrm{s} ). Find the waveform.
A ( cdot y=(10 mathrm{cm}) sin left(30 t pm frac{3}{2} x+phiright) )
B. ( y=(20 c m) sin left(30 t pm frac{3}{2} x+phiright) )
c. ( y=(10 mathrm{cm}) sin left(60 t pm frac{3}{2} x+phiright) )
D. ( y=(20 mathrm{cm}) sin left(60 t pm frac{3}{2} x+phiright) )
11
707Tuning fork ( C ) of frequency 305 Hz gives 5 beats/sec with tuning fork D when sounded together. When prongs of D are filled a little they produce 3 beats/s. The frequency of tuning fork D before filling is:
A . 310 ( mathrm{Hz} )
в. зоо нz
c. 295 н
D. 315 нz
11
708Two particles undergo SHM along same line with same time period (T) and same amplitude
(A) At particular instant one particle is ( x=-A ) and the other is at ( x=0 ) If they move in same
direction then they will meet each other
at
A ( cdot x=frac{A}{2} )
в. ( x=frac{A}{sqrt{2}} )
c. ( x=frac{A}{4} )
D. ( x=frac{4}{8} )
11
709Find odd man out:
Give reason for your answer.
11
710When a sound wave travels from one
medium to another, the quantity that remains unchanged is
A. Speed
B. Amplitude
c. Frequency
D. wavelength
11
711A taut string for which ( mu=5.00 times )
( 10^{-2} k g / m ) is under a tension of ( 80.0 mathrm{N} )
How much power must be supplied to the string to generate sinusoidal waves at a frequency of ( 60.0 mathrm{Hz} ) and an
amplitude of ( 6.00 mathrm{cm} ? )
11
712Fill the vacant space with the suitable
option. A wave transfers from
one location to another.
A. energy, but not matter
B. matter, but not energy
c. both energy and matter
D. neither energy nor matter
E. Waves do not transfer anything across locations
11
713A uniform string of length ( l ), fixed at
both ends is vibrating in its ( 2 n d )
overtone. The maximum amplitude is ‘a
and tension in string is ‘T’, if the energy of vibration contained between two
consecutive nodes is ( frac{K}{8} cdot frac{a^{2} pi^{2} T}{l} ) then ( ^{prime} K ) is
11
714The equation of a progressive wave is ( boldsymbol{y}=mathbf{8} sin left[boldsymbol{pi}left(frac{boldsymbol{t}}{mathbf{1 0}}-frac{boldsymbol{x}}{mathbf{4}}right)+frac{boldsymbol{pi}}{mathbf{4}}right] . ) The
wavelength of the wave is
( mathbf{A} cdot 8 m )
B. ( 4 m )
c. ( 2 m )
D. ( 10 mathrm{m} )
11
715For a wave propagating in a medium, identify the property that is independent of the others
A. Velocity
B. Wavelength
c. Frequency
D. All these depend on each other
11
716When a sound is reflected from a
distinct object, an echo is produced. Let the distance between the reflecting surface and the source of sound
production remains the same. Do you hear echo sound on a hotter day?
11
717A series of ocean waves, each ( 5.0 mathrm{m} )
from crest to crest, moving past the observer at a rate of 2 waves per second
What is the velocity of ocean waves?
A. ( 2.5 mathrm{m} / mathrm{s} )
B. ( 5.0 mathrm{m} / mathrm{s} )
( c cdot 8.0 mathrm{m} / mathrm{s} )
D. ( 10.0 mathrm{m} / mathrm{s} )
11
718The expression ( y=a sin b x sin omega t )
represents a stationary wave. The distance between two consecutive
nodes is –
( A cdot frac{pi}{b} )
в. ( frac{pi}{2 b} )
( c cdot frac{2 pi}{b} )
D.
11
719Speed of sound wave in a given medium
is
A. Directly proportional to its frequency
B. Inversely proportional to its frequency
C. Directly proportional to the square of frequency
D. Independent of its frequency
11
720Five waveforms moving with equal
speeds on the x-axis
( boldsymbol{y}_{1}=boldsymbol{8} sin (boldsymbol{omega} boldsymbol{t}+boldsymbol{k} boldsymbol{x}) ; boldsymbol{y}_{2}= )
( 6 sin left(omega t+frac{pi}{2}+k xright) ; y_{3}= )
( mathbf{4} sin (omega t+pi+k x) )
( boldsymbol{y}_{4}=2 sin left(omega t+frac{3 pi}{2}+k xright) )
( boldsymbol{y}_{5}=4 sqrt{2} sin left(omega t-k x+frac{pi}{4}right) ) are
superimposed on each other. The resulting wave is:
( ^{mathrm{A}} cdot_{8 sqrt{2} cos k x sin left(omega t+frac{pi}{4}right)} )
B. ( 8 sqrt{2} sin left(omega t-k x+frac{pi}{4}right) )
c. ( quad 8 sqrt{2} sin k x cos left(omega t+frac{pi}{4}right) )
( mathbf{D} cdot 8 sin (omega t+k x) )
11
721The ratio of speeds of sound in hydrogen gas and oxygen gas at same temperature will be
A . 8: 1
в. 4: 1
( mathrm{c} cdot 1: 8 )
D. 1: 4
11
722A progressive wave of frequency
( mathbf{5 0 0} boldsymbol{H z} ) is travelling with a velocity of
( 360 m s^{-1} . ) The distance between two
point ( 60^{circ} ) out of phase is
A ( .2 .1 m )
B. ( 0.12 m )
c. ( 0.21 m )
D. ( 1.2 m )
11
723In the equation ( boldsymbol{y}= )
( boldsymbol{A} sin left(boldsymbol{k} boldsymbol{x}-boldsymbol{omega} boldsymbol{t}+boldsymbol{phi}_{0}right) ) the term phase is
defined as:
( A cdot phi_{0} )
B. ( phi_{0}-omega t )
c. ( k x+phi_{0} )
D. ( k x-omega t-phi_{0} )
11
724A boat at anchor is rocked by a wave whose crests are 100 m apart and
whose velocity is ( 25 m s^{-1} ).how often does the crest reach the boat?
A . ( 2500 s )
B. ( 1500 s )
c. ( 4.0 s )
D. ( 0.25 s )
11
725A plane progressive wave is
represented by the equation ( boldsymbol{y}= ) ( 0.25 cos (2 pi t-pi x) . ) The equation of a
wave with double the amplitude and half the frequency but travelling in the opposite direction will be
A. ( y=0.5 cos (pi t-pi x) )
B. ( y=0.5 cos (pi t+pi x )
c. ( y=0.25 cos (pi t+2 pi x) )
D. ( y=0.5 cos (2 pi t+2 pi x) )
11
726The equation ( boldsymbol{y}= ) ( 5 sin (3 x / 50) cos (450 t) ) represents the
stationary wave setup in a vibrating sonometer wire, where ( x, y ) are in ( c m ) and ( t ) in second. The velocity of
one of the two progressive waves in that stationary wave is
A. ( 2.7 m s-1 )
B. ( 27 m s^{-1} )
c. ( 7.5 m s^{-1} )
D. ( 75 mathrm{ms}^{-1} )
11
727The frequency of a fork is 500 Hz. The
velocity of sound in air is ( 350 mathrm{ms}^{-1} ). The
distance through which sound travels
by the time the fork makes 125 vibrations is
( mathbf{A} cdot 87.5 m )
B. ( 700 m )
c. ( 1400 m )
D. ( 1.75 m )
11
728A plane sound wave passes from medium 1 into medium ( 2 . ) The speed of
sound in medium 1 is ( 200 mathrm{m} / mathrm{s} ) and in
medium 2 is ( 100 mathrm{m} / mathrm{s} ). The ratio of
amplitude of the transmitted wave to that of incident wave is
A. ( frac{3}{4} )
в. ( frac{4}{5} )
c. ( frac{5}{6} )
D. ( frac{2}{3} )
11
729Speed of sound in air is ( 350 m s^{-1} )
fundamental frequency of an open
organ pipe of ( 50 mathrm{cm} ) length will be
( mathbf{A} cdot 175 H z )
в. ( 350 H z )
c. ( 700 H z )
D. ( 500 H z )
11
730Elastic waves need material medium
for their propagation.
A. True
B. False
11
731In deriving the speed of sound in air, Newton assumed that the wave travels
in
A. Adiabatic condition
B. Isothermal condition
c. Isobaric condition
D. Isoclinic condition
11
732Three one dimensional mechanical
waves in an elastic medium is given as
and
( boldsymbol{y}_{1}=mathbf{3} boldsymbol{A} sin (boldsymbol{omega} boldsymbol{t}-boldsymbol{k} boldsymbol{x}) )
( boldsymbol{y}_{2}=boldsymbol{A} sin (boldsymbol{omega} boldsymbol{t}-boldsymbol{k} boldsymbol{x}+boldsymbol{pi}) )
( boldsymbol{y}_{3}=2 boldsymbol{A} sin (boldsymbol{omega} boldsymbol{t}+boldsymbol{k} boldsymbol{x}) )
are superimposed with each other. The
maximum displacement amplitude of the medium particle would be
( A cdot 4 A )
B. 3A
c. ( 2 A )
D. A
11
733An observer moves towards a stationary source of sound with a speed ( 1 / 5^{t h} ) of the speed of sound. The wavelength and frequency of the source emitted are ( lambda )
and ( f ) respectively. The apparent frequency and wavelength recorded by the observer are respectively:
A. ( 1.2 f, 1.2 lambda )
B. ( 1.2 f, lambda )
c. ( f, 1.2 lambda )
D. ( 0.8 f, 0.8 lambda )
11
734You are provided with three similar, but slightly different, tuning forks, when ( A ) and B are both struck, a beat frequency
of ( f_{A B} ) is heard. When ( A ) and ( C ) are both
struck, beat frequency of ( boldsymbol{f}_{A C} ) is heard. It
was noticed that ( boldsymbol{f}_{A B}<boldsymbol{f}_{A C} ). This
experiment is repeated after coating tuning fork A with a little wax. Now it is
observed that values of both ( f_{A B} ) and
( boldsymbol{f}_{A C} ) increase. Which tuning fork has the highest frequency?
( A cdot A )
B. B
c.
D. The answer cannot be determined from the information given
11
735Two sound waves having a phase
difference of ( 60^{circ}, ) have a path difference
of :
( A cdot frac{lambda}{3} )
B. ( frac{lambda}{6} )
( c cdot frac{lambda}{9} )
D. ( lambda )
11
736The effects are produced at a given point in space by two waves described
by the equations ( y_{1}=y_{m} sin omega t ) and
( boldsymbol{y}_{2}=boldsymbol{y}_{m} sin (omega t+phi) ) where ( boldsymbol{y}_{m} ) is the
same for both the waves and ( phi ) is a
phase angle. Tick the correct statement
among the following
A. the maximum intensity that can be achieved at a point is twice the intensity of either wave and occurs if ( phi=0 )
B. the maximum intensity that can be achieved at a point is four times the intensity of either wave and occurs if ( phi=0 )
c. the maximum amplitude that can be achieved at the point its twice the amplitude of either wave and occurs at ( phi=0 )
D. When the intensity is zero the net amplitude is zero and at this point ( phi=pi / 4 )
11
737A transverse sine wave of amplitude 10cm and wavelength 200cm travels from left to right along a long horizontal stretched string with a speed of 100cm / s. Take the origin at left end of the string. At time ( t=0 ), the left end of
the string is at the origin and is moving downward. Then the equation of the wave will be (in C.G.S. system)
A. ( 10 sin (0.01 pi x-pi t) )
В. ( 10 sin (0.02 pi x-pi t) )
11
738If the density of materials of two strings of same length, tension and area of cross-section are 2 kgm ( ^{-3} ) and
( 4 k g m^{-3} ) respectively then the ratio of their frequencies will be
A. ( 1: sqrt{2} )
2 ( : sqrt{2} cdot sqrt{2} )
B . 2: 1
c. 1: 2
D. ( sqrt{2}: 1 )
11
739Two waves, each having a frequency of ( 100 H z ) and a wavelength of ( 2.0 mathrm{cm} ) are travelling in the same direction on a string. What is the phase difference between the waves
( (a) ) if the second wave was produced ( 0.015 s ) later than the first one at the same
place,
(b) if the two waves were produced at a same instant but the first one was produced a distance ( 4.0 mathrm{cm} ) behind the second one?
( (c) ) If each of
the waves has an amplitude of ( 2.0 m m ) what would be the amplitudes of the resultant waves in part
( (a) ) and
( (b) ? )
11
740If you set up the seven overtone on a string fixed at both ends, how many nodes and antinodes are set up in it?
A .6,5
в. 5,4
c. 4,3
D. 3,2
11
741Elastic waves in solid are
A. Transverse
B. Longitudinal
c. Either transverse or longitudinal
D. Neither transverse nor longitudinal
11
742Two strings ( A ) and ( B ) with ( mu=2 k g / m )
and ( mu=8 k g / m ) respectively are joined
in series and kept on a horizontal table with both the ends fixed. The tension in
the string is ( 200 mathrm{N} ). If a pulse of amplitude ( 1 mathrm{cm} ) travels in ( mathrm{A} ) towards the junction, then find the amplitude of reflected and transmitted pulse.
A ( . A_{r}=2 A_{T}=7 )
в. ( _{A_{r}}=frac{-1}{3} A_{T}=frac{2}{3} )
c. ( A_{r}=8 A_{T}=9 )
D. ( A_{r}=3 A_{t}=4 )
11
743The frequency of light in air is ( 5 times ) ( 10^{14} H z . ) What will be the frequency of
light, when it enters in the water?
A ( .2 .5 times 10^{14} mathrm{Hz} )
В. ( 5 times 10^{14} mathrm{Hz} )
( mathbf{c} cdot 10^{15} H z )
D. 2.5 ( times 10^{12} mathrm{Hz} )
11
744From a point source, if amplitude of
water at a distance ‘r’ is A, its amplitude at a distance ‘2r’ will be
( A cdot A )
B. 2A
c. A/2
D. A/4
11
745The vibration in the stem of tuning fork
are
A. transverse
B. longitudinal
c. both
D. none of these
11
746Two light waves are represented by
( boldsymbol{y}_{1}=mathbf{4} sin omega boldsymbol{t} ) and ( boldsymbol{y}_{2}=boldsymbol{3} sin left(boldsymbol{omega} boldsymbol{t}+frac{pi}{2}right) )
The resultant amplitude due to interference will be
A ( .5 mathrm{cm} )
B. ( 7 mathrm{cm} )
c. ( 1 mathrm{cm} )
D.
11
747Two cars are moving on perpendicular
roads. When ear- 1 sounds a horn of
frequency ( n, ) then the apparent
frequency of sound heard by car-2 is is velocity of sound)
A ( cdot nleft[frac{V_{1}+V_{2}}{V_{1}-V_{2}}right. )
B. ( nleft[frac{V_{1}+V_{2} cos theta_{2}}{V_{1}-V_{2} cos theta_{1}}right. )
C ( cdot nleft[frac{V cos theta_{2}}{V_{1} cos theta_{1}}right] )
D. ( nleft[frac{V+2 v_{0} cos theta_{1}}{V-2 V_{1} cos theta_{2}}right. )
11
748The relation between frequency ( (n) ) and
wavelength ( (lambda) ) of a sound wave is given
by
( (v text { is velocity, } n text { is frequency and } T ) is time-period)
A ( . v=n lambda )
В. ( n=-v lambda )
c. ( v=frac{n}{2 lambda} )
D. ( n=frac{T}{lambda} )
11
749The equation of a sound wave is ( y= ) ( 0.0015 sin (62.8 x+316 t), ) the wave
length of this wave is
A. ( 0.2 u n i t )
B. 0.1 unit
c. 0.3 unit
D. ( 0.5 u n i t )
11
750A train approaching a railway crossing at a speed of ( 180 k m h^{-1} ) sounds a short
whistle at a frequency ( 600 H z ), when it
is ( 400 m ) away from the crossing. The
speed of sound in air is ( 340 m s^{-1} ). The
frequency of the sound heard by a person standing on a road perpendicular to the track at a distance of ( 300 m ) from the crossing is:
( mathbf{A} cdot 680 H z )
в. ( 480 H z )
( c cdot 40 H z )
D. ( 50 H z )
11
751Which is a correct representation the
propagation of sound waves in gases?
( A )
B.
C. Either A or B
D. None of these
11
752Assertion
Sound is considered a longitudinal
wave
Reason
Longitudinal waves cause the medium to vibrate parallel to the direction of the
wave
A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
c. Assertion is correct but Reason is incorrect
D. Both Assertion and Reason are incorrect
11
753If piano tuner wants to correct the sound of a string which plays at a lower pitch, What should he do?
A. Tighten the string to make the fundamental frequency higher
B. Tighten the string to make the fundamental frequency lower
C. Loosen the string to make the fundamental frequency higher
D. Loosen the string to make the fundamental frequency lower
E. Find a harmonic closer to the desired pitch
11
754Equations of a stationary and a travelling waves are as follows, ( boldsymbol{y}_{1}= )
( a sin k x cos omega t ) and ( y_{2}=a sin (omega t-k x) )
The phase difference between two points ( x_{1}=frac{pi}{3 k} ) and ( x_{2}=frac{3 pi}{2 k} ) are ( phi_{1} ) and
( phi_{2} ) respectively for two waves. The ratio ( frac{phi_{1}}{phi_{2}} ) is
A.
в. ( 5 / 6 )
( c .3 / 4 )
D. 6/7
11
755A sounding body of negligible dimension emitting a frequency of 150 ( mathrm{Hz} ) is dropped from a height. During its fall under gravity it passes near a balloon moving up with a constant velocity of ( 2 mathrm{m} / mathrm{s} ) one second after it stared to fall. The difference in the
frequency observed by the man in balloon just before and just after crossing the body will be :
(Given that – velocity of sound ( = )
( mathbf{3 0 0 m / s ; g}=mathbf{1 0 m / s ^ { 2 }} )
A . 12
B. 6
( c cdot 8 )
D. 4
11
756The Sl unit of amplitude of oscillation is
A ( . c m )
в. ( m )
( c . k m )
D. ( mu ) m
11
757Energy is not propagated by
A. stationary waves
B. electromagnetic waves
C. longitudinal progressive waves
D. transverse progressive Waves
11
758A wave travelling along the x-axis is described by the equation ( boldsymbol{y}(boldsymbol{x}, boldsymbol{t})= )
( 0.005 cos (alpha x-beta t) ) if the wavelength
and the time period of the wave are ( 0.08 m ) and ( 2.0 s ) respectively, then ( alpha )
and ( beta ) in appropriate units are
A. ( alpha=25.00 pi, beta=pi )
B. ( alpha=frac{0.08}{pi}, beta=frac{2.0}{pi} )
c. ( alpha=frac{0.04}{pi}, beta=frac{1.0}{pi} )
D. ( alpha=12.50 pi, beta=frac{pi}{2.0} )
11
759In a mixture of gases. the average number of degrees of freedom per molecule is ( 6 . ) The rms speed of the molecules of the gas is c. The velocity of sound in the gas is xc/3. Find ( x )11
760A water wave in a shallow tank passes
through a gap in a barrier. What
happens to the speed and what happens
to the wavelength of the wave as it
passes through the gap?
A. speed – decreases ; wavelength – decreases
B. speed – decreases ; wavelength – remains constant
C. speed – remains constant; wavelength – decreases
D. speed – remains constant; wavelength – remains constant
11
761For energy density, power and intensity of any wave choose the correct options.
A ( cdot u= ) energy density ( =frac{1}{2} rho omega^{2} A^{2} )
B. ( P= ) power ( =frac{1}{2} rho omega^{2} A^{2} v )
c. ( _{I}= ) intensity ( =frac{1}{2} rho omega^{2} A^{2} S v )
D. ( _{I}=frac{P}{S} )
11
762Exercise:
[ A transverse harmonic wave on a
string is described by ( boldsymbol{y}(boldsymbol{x}, boldsymbol{t})=mathbf{3} . mathbf{0} sin (mathbf{3 6} boldsymbol{t}+mathbf{0 . 0 1 8} boldsymbol{x}+boldsymbol{pi} / mathbf{4}) )
where ( x ) and ( y ) are in ( c m ) and ( t ) in s. The
positive direction of ( x ) is from left to right. For the wave described in the above
Exercise, plot the displacement ( (y) )
versus
(t) graphs for ( x=0,2 ) and ( 4 mathrm{cm} ) What are the shapes of these of these
graphs? In which aspects does the oscillatory motion in travelling wave differ from one point to another:
amplitude, frequency or phase?
11
763The equation of a stationary wave is
( boldsymbol{Y}=mathbf{1 0} sin frac{boldsymbol{pi} boldsymbol{x}}{boldsymbol{4}} cos 20 boldsymbol{pi} boldsymbol{t} . ) The distance
between two consecutive nodes in
meters is –
( A cdot 4 )
B. 2
( c cdot 5 )
D. 8
11
764The waves which propagate in metals
are
A . Longitudinal
B. Transverse
C. Both (a) and (b)
D. None of these
11
765During reflection of sound waves against a wall, which of the following properties not change?
A. Frequency
B. Speed
c. wavelength
D. All of them
11
766A tension in wire is ( 40 mathrm{N} ) and ( 10 mathrm{m} ) of wire
has a mass of ( 0.01 mathrm{kg} ). The speed of transverse waves in ( mathrm{m} / mathrm{s} ) in the wire is :
A . 200
B. 80
( c .300 )
D. 180
11
767A sonometer wire ( 110 mathrm{cm} ) long produces a resonance with a tuning fork. When its length is decreased by ( 10 mathrm{cm}, 9 ) beats per second are heard. The frequency of tuning fork is
( mathbf{A} cdot 90 mathrm{Hz} )
B. 85 Н Н
c. 82 Нz
D. ( 75 mathrm{Hz} )
11
768A speaker emits a sound wave of
frequency ( f_{0} . ) When it moves towards a stationary observer with speed ( u ). The
observer measures a frequency ( f_{1} ). If the
speaker is stationary, and the observer
moves towards it with speed ( u, ) the
measured frequency is ( f_{2} ). Then
A ( cdot f_{1}=f_{2}f_{2} )
c. ( f_{1}f_{0} )
11
769Two wires are kept tight between the
same pair supports. The tensions in the wires are in the ration ( 2: 1, ) the radii are
in the ratio 3: 1 and the densities are in
the ratio ( 1: 2 . ) The ratio of their
fundamental frequencies is
A .2: 3
B. 2: 4
c. 2: 5
D. 2: 6
11
770Assertion
In a sinusoidal travelling wave on a string potential energy of deformation of string element at extreme position in maximum.
Reason
The particles in sinusoidal travelling wave perform SHM.
A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
c. Assertion is correct but Reason is incorrect
D. Assertion is incorrect but Reason is correct
11
771The isothermal elasticity of a medium
is ( mathrm{E}_{i} ) and the adiabatic elasticity in ( mathrm{E}_{a} )
The velocity of sound in the medium is proportional to
( mathbf{A} cdot E_{j} )
в. ( E_{a} )
c. ( sqrt{E_{i}} )
D. ( sqrt{E_{a}} )
11
772The waves are represented by the following equations
( boldsymbol{y}_{1}=mathbf{5} sin 2 boldsymbol{pi}(mathbf{1 0} boldsymbol{t}-mathbf{0 . 1} boldsymbol{x}) )
( boldsymbol{y}_{2}=mathbf{1 0} sin 2 pi(mathbf{2 0} boldsymbol{t}-mathbf{0 . 2} boldsymbol{x}) )
Ratio of intensities ( frac{boldsymbol{I}_{2}}{boldsymbol{I}_{1}} ) will be :
( mathbf{A} cdot mathbf{1} )
B. 2
( c cdot 4 )
D. 16
11
773If a sitar string is plucked at about ( frac{1}{4} ) th of its length, then the most prominent harmonic would be
A. second
B. third
c. fourth
D. eight
11
774Which one of following is not a longitudinal wave?
A. Ultrasonic wave
B. Infrasonic wave
c. Infrared wave
D. Seismic wave
11
775The velocity of sound in a gas in which two waves of wavelengths ( 50 mathrm{cm} ) and
( 50.5 mathrm{cm} ) produces 6 beats per second is?
A. ( 303 mathrm{m} / mathrm{s} )
B. ( 332 mathrm{m} / mathrm{s} )
c. ( 296 mathrm{m} / mathrm{s} )
D. ( 228 mathrm{m} / mathrm{s} )
11
776is the
distance between consecutive
corresponding points of the same
phase, such as crests, troughs, compressions, rarefactions or zero crossings and is a characteristic of
both travelling waves and standing waves, as well as other spatial wave
patterns.
A. frequency
B. amplitude
c. wavelength
D. none of these
11
777In the given figure pulleys are massless and frictionless and string A are light
and inextensible. A force is applied on pulley A vertically upward. At any time
acceleration of ( 5 mathrm{kg} ) is ( a_{1} ) (upward) and
( 10 mathrm{kg} ) is ( a_{2}(text { upward }) ) then ( left(g=10 m / s^{2}right) )
A ( cdot a_{1}=0, a_{2}=0 ) if ( F=100 N )
B . ( a_{1}=5 m / s^{2}, a_{2}=0 ) if ( F=300 N )
C ( cdot a_{1}=15 m / s^{2}, a_{2}=2.5 m / s^{2} ) if ( F=500 N )
D. All option is correct
11
778Two interfering waves have the same wavelength, frequency, and amplitude. They are traveling in the same direction
but are ( 90^{circ} ) out of phase. Compared to the individual waves, the resultant wave
will have the same.
A. amplitude and velocity but different wavelength
B. amplitude and wavelength but different velocity
c. wavelength and velocity but different amplitude
D. amplitude and frequency but different velocity
11
779A stretched string is in unison with a
tuning fork of frequency ( 392 mathrm{Hz} ). If the length of the string is decreased by ( 2 % ) the number of beats heard per second is nearly
( A cdot 2 )
B. 4
( c cdot 8 )
D. 16
11
780Sound wave is travelling along positive x-direction. Displacement (y) of
particles from their mean positions at
position ( x ) is shown in figure. Choose the correct alternative(s):
This question has multiple correct options
A. particle located at E has its velocity in negative x direction
B. particle located at D has zero velocity
C. particles located near C are under compression
D. change in pressure at D is zero
11
781When waves of same intensity from two coherent sources reach a point with
zero path difference the resultant intensity is ( K ) when the above path difference is ( lambda / 4 ) the intensity becomes:
( A cdot K )
в. ( frac{K}{2} )
c. ( frac{K}{4} )
D. ( frac{K}{8} )
11
782A transverse wave is travelling along a
string from left to right. The figure
represents the shape of the string (snap-shot) at a given instant. At this
instant how many points will have downward magnitude of velocity.
11
783The angle between particle velocity and wave velocity in a transverse wave is:
A. zero
в. ( pi / 4 )
c. ( pi / 2 )
D.
11
784write a general expression for the wave
function
( y=(15 mathrm{cm}) sin left[left(16 pi s^{-1}right) t-left(frac{pi mathrm{rad}}{20 mathrm{cm}}right) x+frac{pi}{2}right] )
( y=(30 mathrm{cm}) sin left[left(16 pi s^{-1}right) t-left(frac{pi r a d}{20 mathrm{cm}}right) x+frac{pi}{2}right] )
( y=(15 mathrm{cm}) sin left[left(8 pi s^{-1}right) t-left(frac{pi mathrm{rad}}{20 mathrm{cm}}right) x+frac{pi}{2}right] )
( y=(15 mathrm{cm}) sin left[left(16 pi s^{-1}right) t-left(frac{pi r a d}{10 mathrm{cm}}right) x+frac{pi}{2}right] )
11
785A progressive wave is represented as ( boldsymbol{y}=mathbf{0 . 2} cos boldsymbol{pi}left(mathbf{0 . 0 4 t}+mathbf{0 . 2 x}-frac{boldsymbol{pi}}{mathbf{6}}right) ) where
distance is expressed in cm and time in second. What will be the minimum
distance between two particles having
the phase difference of ( frac{pi}{2} ? )
A. ( 4 mathrm{cm} )
B. ( 8 mathrm{cm} )
c. ( 25 mathrm{cm} )
D. 12.5 cm
11
786In stationary wave, antinodes are the
points where there is
A. Minimum displacement and minimum pressure change
B. Minimum displacement and maximum pressure change
C. Maximum displacement and maximum pressure change
D. Maximum displacement and minimum pressure change
11
787The point (s) moving upward is/are:
4
B
( c )
D
11
788When stationary waves are set up, pick
out the correct statement from the
following:
A. all the particles in the medium are in the same phase of vibration at all times and distances
B. the particles with an interval between two consecutive nodes are in phase, but the particles in two such consecutive intervals, are of opposite phase
C. the phase lag along the path of the wave increases as the distance from the source increases
D. only antinodes are in same phase
11
789A wave equation which gives the displacement along the y-direction is given by ( boldsymbol{y}=mathbf{1 0} sin (mathbf{6 0} t+mathbf{2} boldsymbol{x}) ) where ( boldsymbol{x} )
and ( y ) are in metres and ( t ) is time in
seconds. This represents a wave This question has multiple correct options
A. travelling with a velocity of ( 30 mathrm{m} / mathrm{s} ) in the negative ( x- ) direction
B. of wavelength ( pi mathrm{m} )
c. of frequency ( frac{30}{pi} H )
D. of amplitude ( 10 m )
11
790Wave number is given by:
A. ( frac{2 pi}{text { wavelength }} )
в. ( frac{2 pi}{text { frequency }} )
c. ( frac{2 pi}{text { time period }} )
D. none of these
11
791Two tuning folks with natural frequencies ( 340 mathrm{Hz} ) each move relative
to a stationary observer. One fork moves away from the observer, while the other moves towards him at the same speed. The observer hears beats of frequency 3
Hz. Find the speed of the tuning fork. (Velocity of sound in air ( =330 mathrm{m} / mathrm{s} ) )
11
792x-y curve at an instant for a wave
travelling along ( x ) axis on a string is shown. Slope at the point ( A ) on the curve,
as shown, is ( 53^{circ} )
This question has multiple correct options
A. Transverse velocity of the particle at point A is positive if the wave is travelling along the positive x axis.
B. Transverse velocity of the particle at point A is positive if the wave is travelling along the negative x axis of the particle at point ( A )
C. The magnitude of transverse velocity of the particle at point A is greater than the wave speed.
D. The magnitude of the transverse velocity of the particle at point A is lesser than wave speed
11
793The displacement of the medium in a sound wave is given by the equation
( boldsymbol{y}_{1}=boldsymbol{A} cos (boldsymbol{a} boldsymbol{x}+boldsymbol{b} boldsymbol{t}) ) where ( boldsymbol{A}, boldsymbol{a} & boldsymbol{b} ) are
positive constants. The wave is reflected by an obstacle situated at
( boldsymbol{x}=mathbf{0} . ) The intensity of the reflected
wave is 0.64 times that if the incident
wave
(a) What are the wavelength and frequency of the incident wave?
(b) Write the equation for the reflected
wave.
(c) In the resultant wave formed after
reflection, find the minimum value of
the particle speed in the medium?
11
794When a source emits light of particular wavelength and the source is moving away from us, the wavelength appears
A . Longer
B. First longer and then shorter
c. Unaltered
D. shorter
11
795A wire having a linear density of 0.05 ( mathrm{gm} / mathrm{cm} ) is stretched between two rigid supports with a tension of ( 4.5 times 10^{7} )
dynes. It is observed that the wire resonates at a frequency of 420 cycles/sec. The next higher frequency at which the same wire resonates is 490
cycles/sec. The length of wire is approximately
A. ( 314 mathrm{cm} )
B. 254 cm
c. ( 214 mathrm{cm} )
D. 354 cm
11
796Beats are produced due to the superposition of two progressive notes of same amplitude. Maximum intensity is ( n ) times the intensity of either note.
The value of ( n ) is :
( A )
B. 2
( c cdot 3 )
D. 4
11
797Two waves of equal amplitude ( x_{0} ) and equal frequency travel in the same
direction in a medium. The amplitude of the resultant wave is
A . 0
B. ( x_{0} )
( c cdot 2 x_{0} )
D. Between 0 and ( 2 x_{0} )
11
798If the frequency of a sound wave is doubled then the velocity of sound will be
A. zero
B. half
c. double
D. unchanged
11
799Two sound waves, each of amplitude ( boldsymbol{A} )
and frequency ( omega, ) superpose at a point with a phase difference of ( frac{pi}{2} ) The amplitude and the frequency of the
resultant wave are, respectively
A ( cdot A^{2}, omega )
B. ( 2 A, omega )
c. ( A, omega )
D. ( sqrt{2} A, omega )
11
800A string vibrates according to equation
( y=sin frac{pi x}{3} cos 40 pi t . ) The potential
energy of the string will be zero at times
( ^{A} cdot frac{1}{20} s ) and ( frac{1}{40} s )
B. ( frac{1}{40} s ) and ( frac{1}{80} s )
( ^{mathrm{c}} cdot frac{1}{80} s ) and ( frac{3}{80} s )
D. ( frac{1}{40} s ) and ( frac{3}{40} s )
11
801The path difference between two waves ( boldsymbol{y}_{1}=boldsymbol{a}_{1} sin left(boldsymbol{omega} boldsymbol{t}-frac{boldsymbol{2} boldsymbol{pi} boldsymbol{x}}{boldsymbol{lambda}}right) ) and ( boldsymbol{y}_{2}= )
( boldsymbol{a}_{2} cos left(boldsymbol{omega} boldsymbol{t}-frac{boldsymbol{2} boldsymbol{pi} boldsymbol{x}}{boldsymbol{lambda}}+boldsymbol{phi}right) )
( ^{A} cdot frac{lambda}{2 pi}[phi+pi / 2] )
в. ( frac{lambda}{2 pi}[phi] )
c. ( frac{lambda}{2 pi}[phi-pi / 2 )
D. ( frac{2 pi}{lambda}[phi )
11
802A wave is travelling on a string with the frequency 4 cycles per second, and its speed is 0.08 meters per second. Calculate the wavelength of the wave?
A . ( 0.25 mathrm{m} )
B. ( 0.55 m )
c. ( 3.125 mathrm{m} )
D. ( 0.02 mathrm{m} )
E. 12.55 m
11
803The equation of a transverse wave is ( boldsymbol{y}=boldsymbol{a} sin 2 boldsymbol{pi}[boldsymbol{t}-(boldsymbol{x} / mathbf{5})], ) then the ratio of
maximum particle velocity and wave velocity is :
A ( cdot frac{2 pi a}{sqrt{5}} )
в. ( frac{2 pi a}{5} )
( c cdot frac{a}{5} )
D. ( 2 pi a sqrt{5} )
11
804Which of the following waves is udsed in sonography?
A. Radio waves
B. X-rays
c. Ultrasonic waves
D. Gamma rays
11
805In an experiment it was found that when a sonometer in its fundamental mode of
vibration and a tuning fork gave 5 beats when length of wire is 1.05 metre or 1 metre. The velocity of transverse waves in sonometer wire when its length is ( 1 mathrm{m} )
A. ( 400 mathrm{m} / mathrm{s} )
B. 210 ( mathrm{m} / mathrm{s} )
c. ( 420 mathrm{m} / mathrm{s} )
D. ( 450 mathrm{m} / mathrm{s} )
11
806The tension, length, diameter and density of a string ( mathrm{B} ) are double than that of another string A. Which of the following overtones of B is same as the fundamental frequency of A?
A . ( 1 s )
B. 2nd
( c .3 r d )
D. 4 th
11
807The equation of a progressive wave is given by ( boldsymbol{y}=mathbf{1 0} sin (mathbf{5} boldsymbol{t}-boldsymbol{x}) . ) The wave
gets reflected from a open boundary The equation of the reflected wave is
A ( . y=10 sin (5 t-x) )
B. ( y=-10 sin (5 t-x) )
c. ( y=10 sin (5 t+x) )
D. ( y=10 sin (5 t+x+pi) )
11
808Find the fundamental frequency and the next three frequencies that could cause a standing-wave pattern on a string that is ( 30.0 mathrm{m} ) long, has a mass per unit length of ( 9.00 times 10^{-3} k g / m ) and is
stretched to a tension of ( 20.0 mathrm{N} )
11
809Two particles on a wave having wavelength ( 2 mathrm{m} ) are at the distances of 5
( mathrm{m} ) and ( 9 mathrm{m} ) respectively from origin. The phase difference between the particles
is
A ( cdot frac{pi}{2} ) rad
B. ( pi ) rad
( c cdot 2 pi ) rad
D. ( 4 pi ) rad
11
810A car is moving towards a hill cliff. The driver sounds a horn of frequency f. The reflected sound heard by the driver has frequency ( 2 f ) if ( v ) the velocity of sound, then the velocity of the car, in units will
be
11
811Two sinusoidal waves of the same
frequency travel in the same direction
along a string. If ( boldsymbol{A}_{mathbf{1}}=mathbf{3 . 0} boldsymbol{c m}, boldsymbol{A}_{mathbf{2}}= )
( 4.0 mathrm{cm}, phi_{1}=0, ) and ( phi_{2}=pi / 2 mathrm{rad}, ) what
is the amplitude of the resultant wave?
11
812A sinusoidal progressive wave is generated in a string. It’s equation is given by ( y=(2 m m) sin (2 pi x- )
( mathbf{1 0 0} pi boldsymbol{t}+boldsymbol{pi} / mathbf{3}) . ) The time when particle
at ( x=4 m ) first passes through mean
position, will be
A ( cdot frac{1}{150} sec )
в. ( frac{1}{12} ) sec
c. ( frac{1}{300} ) sec
D. ( frac{1}{100} ) sec
11
813Statement-1: Superposition principle is applicable only for small disturbances
Statement-2: Superposition principle is applicable only for non-linear waves.
A. If both the statements are true and statement- 2 is the correct explanation of statement-
B. If both the statements are true but statement-2 is not the correct explanation of statement-
c. If statement-1 is true and statement- 2 is false
D. If statement-1 is false and statement-2 is true
11
814Assertion
In a small segment of string carrying sinusoidal wave, total energy is conserved if system is isolated.
Reason

Every small part moves in SHM.
A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
c. Assertion is correct but Reason is incorrect
D. Assertion is incorrect but Reason is correct

11
815The transfer of energy in mechanical waves happens through molecules
A. through collisions
B. through interactions
c. through cohesive forces
D. through electrical forces
11
816Two waves ( Y_{1}=a sin omega t ) and ( Y_{2}= )
( operatorname{asin}(omega t+delta) ) are producing
interference, then resultent intensity is:
A ( cdot a^{2} cos ^{2} delta / 2 )
B . ( 2 a^{2} cos ^{2} delta / 2 )
c. ( 3 a^{2} cos ^{2} delta / 2 )
D. ( 4 a^{2} cos ^{2} delta / 2 )
11
817To determine the position of a point like object precisely light should
be used.
A. polarized
B. short wavelength
c. long wavelength
D. intense
11
818If ( lambda_{1}, lambda_{2}, lambda_{3} ) are the wavelength of the
waves giving resonance to the fundamental, first and second overtone
modes respectively in a string fixed at both ends. The ratio of the wavelengths ( boldsymbol{lambda}_{1}: boldsymbol{lambda}_{2}: boldsymbol{lambda}_{3} ) is
A. 1: 2: 3
B. 1: 3: 5
c. ( 1: frac{1}{2}: frac{1}{3} )
D. ( 1: frac{1}{3}: frac{1}{5} )
11
819A standing wave ( zeta= ) ( (5 m m) sin pi x . cos (200 t) ) is maintained
in a homogeneous rod with cross-
sectional area ( 0.04 m^{2} ) and density
( 1000 k g / m^{3} . ) The total mechanicalenergy confined between the sections corresponding to the adjacent displacement nodes is
A. ( 10 J )
( J )
B. ( 20 J )
c. ( 40 J )
D. None of these
11
820If the wavelength of a sound source is
reduced by a factor of ( 2, ) what happens to the waves frequency? What happens to its speed?
11
821In stationary wave, the distance between a node and its adjacent antinode is
( A cdot lambda )
B. ( frac{lambda}{4} )
( c cdot frac{lambda}{2} )
D. ( 2 lambda )
11
822A pulse on a string is shown in the figure. P is particle of the string. Then state which of the following is incorrect
A. If P is stationary point, then pulse consists of two waves travelling in opposite direction
B. If P is moving upwards, then pulse is travelling in positive direction
C. If P is moving downwards, then pulse is travelling in negative direction
D. none of these is incorrect
11
823A particle executing simple harmonic motion completes
1200 oscillations per minute and
passes through the mean position with a velocity of 3.14 ms( ^{-1} ). Determine the
maximum displacement of the particle
from its mean position. Also obtain the
displacement equation of the particle if it particle if its displacement be zero at the instant ( boldsymbol{t}=mathbf{0} )
11
824In a ripple tank, 10 full ripples/s are produced. The distance between peaks of consecutive trough and crest is 15 ( c m ). Calculate the velocity of the
ripples.
( A cdot 2 m / s )
в. ( 3 m / s )
c. ( 4 m / s )
D. ( 6 m / s )
11
825Two second wave travel out from a
common point have frequencies ( 30 mathrm{Hz} )
and ( 40 mathrm{Hz} ) respectively where phase difference between the after 0.8 second.
( ? )
A . zero
B. ( frac{pi}{4} )
c. ( frac{5 pi}{2} )
D. ( 5 pi )
11
826The separation between the two nearest
points on the string that do not move at all is
A. 0.163 m n ( m ).
в. 0.325 т
c. 0.202 m
D. 0.244 m
E. none
11

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