# Sound Questions

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

Question NoQuestionsClass
1Sonar is an instrument used for finding
the depth of sea. State true or false.
A. True
B. False
9
2There is no atmosphere on moon. Therefore,
A. no sound can be heard
B. sound can be easily heard
c. sound is sometimes heard
D. all the above statements are correct
9
3The sound wave is of the type8
4Assuming the speed of sound in air equal to ( 340 m s^{-1} ) and in water equal to
( 1360 m s^{-1}, ) find the time taken to trave
a distance ( 1700 mathrm{m} ) by sound in water
A . ( 0.8 s )
B. ( 1 s )
c. ( 1.5 s )
D. ( 1.25 s )
9
5Explain how the human ear works.9
6The full name of’SONAR’is.
A. Sonography and Research
9
7The frequency of a wave is 5 Hz. It refers to (type of wave)
A . ultrasonics
B. microwaves
c. infrasonics
9
8What do you mean by the audible range of frequency?9
9State whether given statement is True or False :

There is no possibility of having mixed hearing loss with both conductive and
sensori-neural element.
A. True
B. False

9
10A scientist performed an experiment as shown in the picture above. What happened as air was pumped out of the jar and he rang the bell?
A. The sound became louder
B. The sound became fainter first and then louder once all the air was pumped out
c. The sound could not be heard anymore
D. The sound was the same as before
9
11An echo is heard on a day when
temperature is about ( 22^{0} ) C. The echo
will be heard sooner when the
temperature is ( 40^{0} mathrm{C} ) becuase
A. at higher temperature sound travels faster
B. at higher temperature sound reflects
c. at higher temperature sound travels slower
D. none of these
9
12What type of sound waves can
propagate in solids?
A. Longitudinal only
B. Transverse Only
C. Both longitudinal and transverse
D. Non mechanical waves only
9
13A person in a vehicle is moving away from a vertical mountain with uniform
velocity. When the vehicle is at a distance ( 975 mathrm{m} ) from mountain, the person blows a horn and hears its echo after 6 s. If velocity of sound in air is 340
( mathrm{ms}^{-1}, ) the velocity of the vehicle is :
A. 36 kmph
B. 54 kmph
c. 72 kmph
D. 90 kmph
9
14The ratio of velocity of sound in hydrogen and oxygen at STP is:
( mathbf{A} cdot 16: 1 )
B. 8: 1
c. 4: 1
D. 2: 1
9
15How it is helpful to locate submarines of enemies through SONAR?
A. It produces ultrasound in water
B. It produces infrasonic in water
c. It produces ultrasound and infrasound in water
D. None
9
16What is Reverberation? and How it can
be reduced in an Auditorium?
9
17A sonar device on a submarine sends
out a signal and receives an echo 5 s later. Calculate the speed of sound in water if the distance of the object from the submarine is ( 3625 mathrm{m} )
( A cdot 1450 mathrm{m} / mathrm{s} )
B. 1650 ( mathrm{m} / mathrm{s} )
( c cdot 1350 mathrm{m} / mathrm{s} )
D. ( 967 mathrm{m} / mathrm{s} )
9
18SONAR is based on the principle of
A. echo
B. resonance
c. reverberation
D. anyone of the above
9
19How sound is produced in flute or clarinet?
A. Air in the tube vibrates
B. Skin of flute vibrates
c. The holes of the flute vibrate
D. No vibration is produced
8
20The thin stretched membrane at the end
of the ear canal is
A. Pinna
B. Cochlea
c. Eardrum
D. stapes
9
21If equation of sound wave is ( boldsymbol{y}= )
( 0.0015 sin (62.8 x+314 t) ) then its
wavelength will be:
A. 0.1 unit
B. 0.2 unit
c. 0.3 unit
D. 2 unit
9
22The frequency of sound waves can be
expressed in
A . ( mathrm{Hz} )
B . cycle/second
( c cdot s^{-1} )
D. all the above
9
23A person standing between two parallel
hills fores a gun. He hears the first echo after ( 3 / 2 ) s, and second echo after ( 5 / 2 ) s.
If speed of sound is ( 332 mathrm{m} / mathrm{s} ), calculate the distance between the hills. When
will hear the third echo?
9
24Sound
A. needs a material medium for its propagation
B. does not need a material medium for its propagation
C. can travel without any material medium
D. needs light for travelling
9
25What is the average adult female speaking voice range?
A . ( 125 mathrm{Hz} )
в. 210нz
c. 300 н ( z )
D. 400нz
8
26Represent graphically by two separate diagrams in the case where two sound
waves having the same amplitude but different frequencies:
9
27What type of waves are generated by SONAR device fixed to a fishing ship?
A. water waves
c. sound waves
D. infrared waves
9
28A ship sends a sonar wave to the sea bed which is flat and measured several
times over a large area. One day the reflected sound wave takes longer time than in previous measurements. The possible reason is :
A. the frequency of the sonar wave, generated by the equipment is lower than previous measurements
B. there is a solid object of large size in the path of sonar wave
c. there is a huge air bubble in the path of sonar wave
D. the loudness of the sonar wave, generated by the equipment is lower than previous measurement
9
29Velocity of sound is maximum in-
A. water
B. oil
c. Air
D. Iron
9
30The speed of sound in a perfectly rigid
rod is
A. infinite
в. Zero
( mathrm{c} .332 mathrm{m} / mathrm{s} )
D. ( 3 times 10^{8} mathrm{m} / mathrm{s} )
9
31How far away should a deep sea diver be
from an under-sea rock so that he can
hear his own echo? (Speed of sound in water is ( 1500 mathrm{m} / mathrm{s} ) ).
A. ( 1500 mathrm{m} )
B. 750m
( c cdot 150 m )
D. 75m
9
32A bomb explodes on the moon. How long will it take for the sound to reach the
earth?
A . 10 seconds
B. 1000 seconds
c. 1 day
D. It does not reach the earth
9
33A human heart on an average beat 72 times a minute. Calculate its frequency
( mathbf{A} cdot 72 s^{-1} )
B ( cdot 1.2 s^{-1} )
( mathrm{c} cdot 4320 s^{-1} )
D. None
9
34What is multiple reflection of sound?
A. Process in which sound waves bounces off obstacles and reflects many times before reaching destinations
B. Process in which sound waves penetrates in obstacles and reflects many times before reaching destinations
c. Process in which sound waves bounces off obstacles and deflects one time before reaching destinations
D. None
9
35The membrane of a drum vibrates to
produce sound. Similarly the string of a sitar vibrates to produce sound. Based on these two examples answer the following question. Which part of a whistle vibrates to produce sound?
A. Body of whistle
B. Air
c. Mouth of the person
D. All of the above
8
36The method of detecting the presence, position and direction of motion of distant objects by reflecting a beam of sound waves is known as
B. SONAR
c. мIR
D. ско
9
37Velocity of sound in air is about :
A. ( 330 mathrm{m} / mathrm{s} )
B. ( 460 mathrm{m} / mathrm{s} )
c. ( 380 m / s )
D. ( 400 mathrm{m} / mathrm{s} )
9
38A sound wave passes from a medium A to a medium B. The velocity of sound B is greater than that in A. Assume that
there is no absorption or reflection of the boundary. As the wave moves across
the boundary, the
A. Frequency of sound will increase
B. Wavelength of sound will increase
c. wavelength of sound will decrease
D. Intensity of sound will increase
9
39Which of the following frequency of sound can be heard by a dog but not by a man?
A. 50,000 hertz
B. 15,000 hertz
c. 4200 ohertz
D. none
9
40Which one has higher frequency?
A. Infrasonic sound
B. Ultrasonic sound
C. Audible sound
D. All of the above have same frequency
9
41Which is true for a wave? (here ( n= )
frequency, ( T= ) time period
( mathbf{A} cdot mathbf{n T}=1 )
B. ( frac{n}{T}=2 )
c. ( n=T )
D. None of these
9
42Sound waves travel fastest in.
A. solids
B. liquids
c. gases
D. vacuum
9
43An astronaut can’t hear his companion at the surface of the moon because:
A. Produced frequencies are above the audio frequency
B. There is no medium for sound propagation
C. Temperature is too low during night and too highh during day
D. There are too many craters on the surface of the moon
9
44The sound heard after reflection from a
rigid surface is called echo.
A. True
B. False
9
45A sonar device on a submarine send out
a signal and receives an echo 5 sec later.
Calculate the speed of sound in water, if the distance of object from the submarine is ( 3625 m )
A. ( 1440 mathrm{ms}^{-1} )
B. ( 1460 mathrm{ms}^{-1} )
c. ( 1450 m s^{-1} )
D. ( 1470 mathrm{ms}^{-1} )
9
46Resonance is an example of
A. Tuning fork
B. Forced vibration
C. Free vibration
D. Damped vibration
8
47Name the instruments for which more
than one part is responsible for the production of sound.
( A ). Tabla
B. Violin
c. Guitar
D. All of the above
8
48If eight persons are to address a meeting, then the number of ways in which a specified speaker is to speak before another specified speaker is?
A . 2520
B. 20160
c. 40320
D. None of these
9
49Sound from the outside world reach the
inner ear through:
A. pinna
B. cochlea
c. auditory canal
D. labyrinth
9
50A child inserted a needle in a man’s
ear.the man became deaf. Why?
A. The needle damaged the oval window
B. The needle damaged the stirrup
C. The needle damaged the ear drum
D. All of the above
9
51What do you understand by
Reverberations in relation to sound
waves?
9
52Sound requires a medium to travel
A. True
B. False
9
53A sound wave is travelling from East to West. In which direction do the
molecules in the air move?
A. East to west
B. West to East
c. North to South
D. South to North
9
54A sound wave travelling in air is made to propagate through a liquid such that the velocity of sound is quadrupled. If the frequency of he sound wave is constant, find the change in the wavelength of the sound wave.
A ( cdot lambda_{a i r} )
B. ( 2 lambda_{text {ar }} )
c. ( 3 lambda_{lambda i} )
D. ( 4 lambda_{text {ar }} )
9
55Write any two factors that influence the
speed of sound through air.
9
56The repetition of reflected sound from a distant object is called
A . echo
B. transformation
c. eddy currents
D. string
9
57Vibrating bodies produce
A. Sound
в. Heat
c. Light
D. None of these
8
58Using the SONAR, sound pulses are emitted at the surface of water. These
pulses after being reflected from the bottom are detected. If the time internal
from the emission to the detection of
sound pulses is ( 8 s ), find the depth of
water:
(net of sound in water ( =mathbf{1 4 9 8 m} / boldsymbol{s} ) )
( mathbf{A} cdot 1498 m )
B. ( 5992 m )
c. ( 374.5 m )
D. ( 18182 m )
9
59In violin there is part which is used to adjust the string for getting right pitch. What is the name of that part?
A. Tunning peg
B. Volute
c. Finger board
D. Neck
8
60Match the following and choose the
correct option
( begin{array}{llll}text { A } & text { String vibration } & text { 1. } & text { Tabla } \ text { B } & text { Membrane vibration } & text { 2. } & text { Cymbals } \ text { C } & text { Vibration of air } & text { 3. } & text { Sitar } \ text { D } & text { Vibration of plate } & text { 4. } & text { Flute }end{array} )
( A cdot A-1, B-2, C-3, D-4 )
B. A-2, B-1, C-4, D-3
C. A-3, B-1, C-4, D-2
D. A-4, B-3, C-2, D-1
8
61Mark the incorrect statement
A. Sound can be produced by beating an object irrespective of whether there are vibrations or not.
B. The sound of a tabla normally has a lower pitch than the sound of a violin.
C. A short flute will produce sound of lower pitch than a long flute.
D. All of the above
8
62Veena and Rani are on the moon, Veena
calls out her friend, but Rani does not hear Veena’s call even though she is near. Discuss.
9
63A cars initially at rest, 330m away from a stationary observer. It begins to move towards the observer with an
acceleration of ( 1.1 m s^{-2}, ) sounding its horn continuously. 20 s later, the driver stops sounding the horn. The velocity of sound in air is ( 330 m s^{-1} ). The observer
will hear the sound of the horn for a
duration of
A . ( 20 s )
в. ( 21 s )
( mathrm{c} cdot 20 frac{2}{3} s )
D・ ( 19 frac{1}{3} s )
9
64What does a body produce when it vibrates?
A. Heat
B. Sound
c. Light
D. Electricity
8
65State whether given statement is True or False

In order to transmit sound waves, the
medium should possess elasticity and inertia.
A. True
B. False

9
66The 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 ultra sounds
9
67A staircase has a large number of steps each of width ( 25 mathrm{cm} ) and height ( 20 mathrm{cm} ) A sharp sound is made at a distance in front of the staircase. The frequency of the musical note produced by the echelon effect is (take speed of sound in air as ( 350 mathrm{m} / mathrm{s} ) )
A. 700 Hz
в. 350 нz
c. 437.5 Нz
D. 875 нz
9
68Which part of the ear vibrates when sound waves enter our ear?
A. Ear canal
B. Eardrum
c. Pinna
D. cochlea
9
69Why can’t we hear the scream of bat?
A. Because its scream consists of infrasonic sound
B. Because its scream consists of ultrasonic sound
C. Because its scream consists of subsonic sound
D. None of these
9
70A transverse wave of frequency ( 100 mathrm{Hz} ) passes through water. The refractive index of water is ( 1.33, ) what will be the
frequency of the wave in water
A . 133 Н ( z )
в. 100 Н ( z )
( c cdot 75 mathrm{Hz} )
D. 165 нz
8
71Bats detect the obstacle in their path
by receiving the detected
A. Infrasonic waves
B. Ultrasonic waves
c. Both
D. None
9
72Assertion
Sound waves cannot be polarised.
Reason
Sound waves are longitudinal in nature.
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.
9
73What is the distance travelled by sound in air when a tuning fork of frequency ( 256 H z ) completes 25 vibrations? The
speed of sound in air is ( 343 m s^{-1} )
9
74After working in a factory for a month, a man complains about a ringing in his ears. What might be wrong with him? What do you think may have caused his
problem? What can you suggest to him to prevent further hearing loss?
9
75Describe an activity to show that sound requires a material medium for its
propagation.
9
76Speed of sound is greater in solids than in liquids because.
A. The solids have high elasticity
B. The liquids have high elasticity
c. The atoms in solids are regularly arranged
D. The atom in liquids are closely packed
9
77When do we say sound travels in a medium?
A. When the medium travels.
B. When the particles of the medium travel.
c. When the source travels
D. When the disturbance travels
9
78Why does a guitarist need to tighten the strings of the guitar to get the correct music and sound?
A. Tight strings force the entire guitar to vibrate.
B. It is easy to play a guitar with tight strings.
c. Tight strings look good and enhance the look of the guitar.
D. It is not important to tighten the string
8
79Imagine a cannon being fired on the surface of the moon. Then
A. the sound will be heard at the surface of the earth during all seasons
B. the sound will not be heard at the surface of the earth
c. the sound will be heard at the surface of the earth during the rainy season
D. no sound will be heard on the earth but it can be heard on the moon
9
80Sound waves from outside are collected
by which part of the ear?
A. cochlea
B. malleus
c. pinna
9
81State whether true or false.
Vibration of the ear drum produces sensation of sound in the ears.
A. True
B. False
9
82Tuning fork causes them to vibrate and produce sound. This is due to
A. the two metal prongs of that tuning fork
B. the length of the prongs of that tuning fork
c. the speed of the molecules hit the tuning fork
D. both A and
8
83A microwave and an ultrasonic sound
wave have the same wavelength.
Their frequencies are in the ratio (approximately)
A ( cdot 10^{2} )
B. ( 10^{text {4 }} )
( c cdot 10^{6} )
D. ( 10^{8} )
9
84Describe the bell jar experiment to
prove that sound requires a medium to
propagate.
9
85SONAR works on the Principle of :
A. reflection of sound
B. reflections of waves
C. infrasonic waves.
D. all of the above
9
86Assertion
Sound waves do not travel through
vacuum
Reason
Sound waves are mechanical waves,
which require a medium for their
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
9
87The waves produced by simple
pendulum (having time period 2 seconds) are.
A. Infrasonics
B. Audible
c. Ultrasonic
D. None of these
9
88Sound waves do not travel through:
A. solids
B. liquids
c. gases
D. vacuum
9
89Assertion
Ultrasonic waves are longitudinal
waves of frequency greater than 20,000 ( mathrm{Hz} )
Reason
The maximum frequency of audible sound waves is ( 20,000 mathrm{Hz} )
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
9
90In theatres, big halls., the reverberation of sound is a common problem.
A. True
B. False
9
91The back and forth motion of an object is called
A . vibration
B. rotation
c. translation
D. linear motion
8
92Ultrasound has frequency of vibration
A. between ( 20 mathrm{Hz} ) and ( 20000 mathrm{Hz} )
B. below 20 Hz.
c. above 20000 Hz.
D. between ( 500 mathrm{Hz} ) and ( 10000 mathrm{Hz} )
9
93Sound is produced when your school bell in struck with hammer. Why?8
94Two sounds of same loudness and same
pitch produced by two different instruments differ their:
A. Amplitudes
B. frequencies
c. wave forms
D. All the above
9
95Which waves are used in sonography?
A. Microwaves
B. Infrared rays
D. Ultrasonic waves
9
96A pulse of sound wave travels a distance ( l ) in helium gas in time ( T ) at ( a )
particular temperature. If at the same temperature a pulse of sound wave is propagated in oxygen gas, it will cover
the same distance ( l ) in time.
A . ( 4.36 T )
в. ( 0.23 T )
( c .3 T )
D. ( 0.46 T )
9
97Water waves in a shallow dish are ( 6 mathrm{cm} )
long. At one point, the water moves up and down at a rate of 4.8 oscillations/s.
What is the speed of the water waves?
A. ( 0.288 mathrm{m} / mathrm{s} )
в. ( 0.3 mathrm{m} / mathrm{s} )
c. ( 1.25 mathrm{m} / mathrm{s} )
D. ( 1.2 mathrm{m} / mathrm{s} )
9
98When we hit a thin plastic ruler firmly
on a bench:
A. the free end of the ruler vibrates and produces sound
B. the end held by hand vibrates and produces sound
C . even after it stops vibrating it continues to produce sound
D. none of the above occur
8
99Fill in the blank.
In longitudinal waves, the particles vibrate in direction of
propagation.
A. parallel
B. perpendicular
c. ( 45^{circ} ) inclined
D. ( 60^{0} ) inclined
9
100The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because9
101Only vibrating bodies produce sound. State true or false
A . True
B. False
8
102Echo is produced due to:
A. reflection of sound
B. refraction of sound
c. resonance
D. termination of sound
9
103SONAR is based on the principle of :
A. echo
B. resonance
c. reverberation
D. damping
9
104Bats detect the obstacles in their path
by receiving the reflected
A. infrasonic waves
B. ultrasonic waves
c. micro waves
9
105What is reverberation? How can it be
reduced?
9
106Velocity of sound is maximum among which of the following substances?
A. Iron
B. Mercury
c. water
D. Air
9
107A sine wave of wavelength ( ^{prime} lambda^{prime} ) is travelling in a medium. What is the minimum distance between two
particles of the medium which always have the same speed?
( A cdot lambda )
B. ( frac{lambda}{2} )
( c cdot frac{lambda}{3} )
D. ( frac{lambda}{4} )
9
108Match items given in A suitably with
items given ( B ) and ( C )
begin{tabular}{|c|c|c|}
hline ( mathrm{A} ) & ( mathrm{B} ) & ( mathrm{C} ) \
hline Microphone & Sonar & Electrical energy gets convented to sund energy \
hline Ultra sonic sound & Permanent magnet & Sound energy gets converted to electrical energy Conventiennal source of energy \
hline CNG & Butane & Non-conventional source of energy \
hline
end{tabular}
9
109Which of the following is an elastic
wave?
A. Sound waves
B. Light waves
c. x-rays
8
110The relation between frequency(f) and time period(T) is given by
( A cdot f=T )
B cdot f ( =frac{1}{T} )
( c cdot T=f^{2} )
D. ( T=f^{3} )
9
111Vibrations in a body produce sounds. How do you prove it?8
112Which kind of sound is produced in an earthquake before the main shock wave begins?
A. Ultrasound
B. Infra sound
c. Audible sound
D. One of the above
9
113If you want to hear a train approaching
from far away, it is more convenient to
put the ear to track because
A. it is more convenient to put the ear to the track
B. it is more convenient to put the ear away from the track
c. both can be true
D. none is true
9
114In a good auditorium the reverberation time is
A. 0.17 v/A
B. ( >0.17 ) V/A
c. ( <0.17 ) V/A
D. none of these
9
115Pitch is ( _{-}-_{-}-_{-}-_{-}-_{-} ) as frequency. Fill in the blank.
A. Same
B. Not the same
c. sometime same sometime different
D. All
9
116How do we hear: Match the parts of a
human ear with their functions:
Match the columns:
9
117Who among the following are associated with SONAR?
A. Plumber
B. Doctor
c. carpenter
D. Navigators
9
118Which of the following must be present for a sound wave to travel?
A. medium
B. compression
c. mediary
D. rarefaction
E. vacuum
9
119The response of human ear to sound in
terms of its shrillness is known as:
A. frequency
B. pitch
c. loudness
D. amplitude
9
120SONAR is frequently used by :
A. Austronauts
B. Doctors
c. Engineers
D. Navigators
9
121An object attached to one end of a spring makes 20 vibrations in 10 s. Its frequency is
A. ( 2 mathrm{Hz} )
B. 10 s
c. ( 0.05 mathrm{Hz} )
D. 2s
9
122is a device which is
based on multiple reflection and isused for sending amplified sound in a particular direction
( A ). Bulb horn
B. Megaphone
c. Ear trumpet
D. al
9
123Three boys rahul, raju, and ravi stand at
three places and clap their hands
simultaneously. Calculate the time between the clap and the echo of the clap of each body. Infer how can the
time between the clap and echo of the
clap varied. Velocity of sound in air is
( mathbf{3 3 0} quad boldsymbol{m s}^{-1} )
9
124Two children are at the opposite end of an iron pipe. One struks the end of the pipe with a stone. Calculate the ratio of the time taken by sound waves in air and in iron to reach the other child. Use
speed of sound in (i) air ( =344 m s^{-1} )
and
(ii) iron ( =mathbf{5 1 3 0 m s}^{-1} )
9
125Sound waves travel at ( 350 m s^{-1} )
through warm air and at ( 3500 m s^{-1} )
through brass. The wavelength of a
( mathbf{7 0 0} boldsymbol{H} z ) acoustic wave as it enters
brass from warm air:
A. decrease by a factor 10
B. increase by a factor 20
c. increase by a factor 10
D. decrease by a factor 20
9
126Which of the following are examples of multiple reflections of sound?
A. Stethoscope
B. Sound board
c. Megaphone
D. All of the above
9
127Fill in the blank.
The length of the vocal chords in men and women is approximately and ( _{–}-_{-} ) respectively
A. ( 15 mathrm{mm}, 20 mathrm{mm} )
B. 20 ( mathrm{mm}, 30 mathrm{mm} )
c. ( 20 mathrm{mm}, 15 mathrm{mm} )
D. 25 mm, 15 mm
8
128Which of the following statements about sound waves is correct?
A. Sound waves are not affected by the medium through which it travels.
B. Sound waves travel faster in air than in liquid.
C. Sound waves travel faster in a solid than in liquids and
gases
D. Sound waves cannot travel through a solid.
9
129The ratio of speed of sound in a gas to
that in water vapours at any temperature is. (when molecular weight of gas is 40 gm/mol and for water vapours is 18 gm/mol)
A . 0.75
B. 0.73
( c cdot 0.68 )
D. none of these
9
130During winter, an echo is heard
A. sooner than during summer
B. later than during summer
c. can’t say
D. Not heard
9
131Why do we lose hearing while yawning?
A. Muscles around middle ear contracts
B. Muscles around middle ear expands
C. Muscles around inner ear contracts
D. Muscles around inner ear expands
9
132Velocity of sound in air is ( 340 mathrm{m} / mathrm{s} )
Sound waves of wavelength ( 0.01 mathrm{m} ) from a vibrating body reach your ear through air. Will you be able to hear the sound? Justify your answer.
9
133Assertion
Sound waves do not travel through
vacuum
Reason
Sound waves are mechanical waves
which require a medium for their
propogation
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
9
134With the length of vocal chord, voice
quality
A. changes
B. remains same
c. may or may not change
D. remains same but loudness changes
8
135The part of the ear that transmits sound vibrations to the brain is the
A. cochlea
B. Stirrup
c. Eardrum
D. Auditory nerve
9
136Assertion
Sound waves do not travels through
vacuum.
Reason
The speed of sound is too small when
compared to speed of light.
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
9
137Which one of the following animals can hear infrasound?
A. rhinoceros
B. bat
( c cdot operatorname{dog} )
D. honey bee
9
138What is conductive hearing loss?
A. When outer or middle ear leads to problem and inefficient transfer of sound
B. When inner ear leads to problem and inefficient transfer of sound
C. When only middle ear leads to problem and inefficient transfer of sound
D. When inner and middle ear leads to problem and inefficient transfer of sound
9
139Which of the following is not a part of
the ear?
A. humerus
B. cochlea
c. labyrinth
D. stapes
9
140Out of the following gases under similar condition of temperature and pressure, the velocity of sound will be maximum
in
A. hydrogen
B. nitrogen
c. oxygen
D. chlorine
9
141What is echo?Waht are the necessary
conditions for its occurence? What is
SONAR?How is it used to determine the
depth of an ocean?
9
142How many vocal cords does a person have?
( A cdot 3 )
B.
( c cdot 2 )
( D )
8
143Assertion
Ultrasonic waves are longitudinal
waves of frequency greater than 20,000 ( mathrm{Hz} )
Reason
The maximum frequency of audible sound waves is ( 20,000 mathrm{Hz} )
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
9
144Three different vibrating bodies produce
three types of sounds ( X, Y ) and ( Z . ) Sounds ( mathrm{X} ) and ( mathrm{Y} ) cannot be heared by a man
having normal range of hearing but sound ( Z ) can be heard easily. The sound ( X )
is used in for monitoring nuclear
reactor.The sound similar to that which is
produced during an earthquake before
the main shock wave is generated. What type of sounds are (i) ( mathrm{X} ) (ii) ( mathrm{Y} ), and (iii) ( mathrm{Z} ) ?
A. ( x ) -infrasound
Y-ultrasound
Z- audible sound
B. X-audible sound
Y-infrasound
z-ultrasound
c. X-ultrasound
Y-infrasound
Z-audible sound
D. X-infrasound
Y-audible sound
Z-audible sound
9
145The medium through which the sound travels fastest is empty space.
A. True
B. False
c. Ambiguous
D. Data insufficient
9
146State the speed of sound in air.
A ( cdot 330 k m s^{-1} )
B. ( 330 mathrm{cms}^{-1} )
c. ( 330 m s^{-1} )
D. ( 330 mathrm{mms}^{-1} )
9
147Which of the following will produce
sound through vibration.
A. A plastic scale when bent over the edge of a bench
B. Saying ‘Ah’ for few seconds
C. Plucking a rubber string by fingers
D. All of the above
8
148The persistence of hearing for human beings is not more than
A . ( 1 mathrm{s} )
в. ( frac{1}{5} s )
c. ( frac{1}{10} s )
D. ( frac{1}{2} s )
9
149Sound requires a for
propagation.
A. medium
B. companion
c. lot of energy
D. liquid
9
150Infrasound can be heard by
( A cdot operatorname{dog} )
B. bat
c. rhinoceros
D. human beings
9
151Sketch larynx and explain its function
8
152A man fired a bullet against a wall and
hears an echo after ( 2 s . ) He walks ( 80 m )
towards the wall and fired bullet, such
that he hears echo after ( 1 s ). Find the
distance from wall to the second fired
place
9
153Sound waves need an ………. (elastic, rigid) medium for propagation.9
154What stimulates the auditory nerve?
A. the movement of the three ear ossicles
B. the movement of stirrup
C. the movement of fluid in the cochlea
D. all
9
155State how bats can locate objects in the
dark.
9
156Time in which the vibrating particle completes one vibration is called the time period. Explain.9
157f you want to hear a train approaching from far away then you should:
A. put the ear to the track.
B. put the ear away from the track
c. both can be true
D. none is true
9
158Sound can not travel in9
159When a wave travels through medium
A. particles are transferred from one place to another
B. energy is transferred in a periodic manner
C. energy is transferred at a constant speed
D. none of the above statements is applicable
9
160A bomb explodes on the moon. How long will it take for the sound to reach the
earth?
A. ( 1 d a y )
B. ( 1000 s )
( c .10 s )
D. None of these
9
161If you go on increasing the stretching force on a wire a guitar, its frequency:
A. Increases
B. Decreases
c. Remains unchanged
D. None of the above
9
162Identify the part which vibrates to
produce sound in the following instruments:
(a) Dholak
(b) Sitar
(c) Flute
8
163Which of the following statements is
true?
A. Sound and light both require medium for propogation.
B. Sound can travel through vacuum, but light cannot.
C. Sound needs medium, but light doesn’t need medium for its propogation.
D. Sound and light both can not travel in medium.
9
164A sound wave has a frequency of ( 1 k H z )
and wave length ( 25 c m ), to travel ( 2.2 k m ) it takes:
A ( cdot 2 frac{3}{7} s )
B. ( 80 frac{2}{5} ) min
c. ( frac{5}{4} ) min
D. ( 8 frac{4}{5} s )
9
165toppr
This oscillation is finally transmitted to the fluid filled in inner portion of the ear
termed as inner ear, the motion of the
fluid disturbs hair calls within the inner
ear which transmit nerve impulses to the brain with information that a sound
is present. The three bones present in the middle ear are named as hammer, anvil and stirrup. Out of these the stirrup is the smallest one and this only connects the middle ear to inner ear as
shown in the figure below. The area of stirrup and its extent of connection with
the inner ear limits the sensitivity of the human ear. Consider a person’s eat whose moving part of the eardrum has
an area of about ( 43 mathrm{mm}^{2} ) and the area of
stirrup is about ( 3.2 mathrm{mm}^{2} . ) The mass of
ossicles is negligible. As a result, force exerted by sound wave in air on eardrum and ossicles is same as the
force exerted by ossicles on the inner ear. Consider a sound wave having maximum pressure fluctuation of ( 3 x )
( 10^{-2} ) Pa from its normal equilibrium
pressure value which is wqual to ( 10^{5} ) Pa Frequency of sound wave is ( 1200 mathrm{Hz} ) Data: Velocity of sound wave in air is ( 332 mathrm{m} / mathrm{s} ). Velocity of sound wave in fluid (present in inner ear) is ( 1500 mathrm{m} / mathrm{s} ). Bulk
modulus of air is ( 1.42 times 10^{5} ) Pa. Bulk
modulus of fluid is ( 2.18 times 10^{9} ) Pa.
Find the pressure amplitude of given sound wave in the fluid of inner ear.
A. 0.03 Pa
B. ( 0.04 mathrm{Pa} )
c. ( 0.3 mathrm{Pa} )
D. ( 0.4 mathrm{Pa} )
9
166Sound travels at the fastest speed in
A. steel
B. water
( c . ) air
D. vacuum
9
167Three different vibrating bodies produce three types of sounds ( X, Y ) and ( Z ) Sounds ( X ) and ( Y ) cannot be heard by a
man having normal range of hearing but sound ( Z ) can be heard easily. The sound ( X ) is used to find faults and
cracks in metals.The sound similar to
that which is produced during an earthquake before the main shock wave is generated.
Name one device which can produce
sound like ( X )
A. Megaphone
B. SONAR
c. Bulb horn
D. Ear mufflers
9
168Mark the incorrect statement
A. During motion of waves, energy is transferred from one point to another
B. All vibrating bodies produce sound
C. A transverse wave consists of crests and troughs
D. Transverse wave can propagate through any medium
9
169A person bangs on a copper pipe that is part of a large warehouse. The sound
can be heard in the pipe 100.0 meters away in 0.02174 seconds.
If the frequency of the sound is
( mathbf{5 0 0 . 0} boldsymbol{H z}, ) what is the wavelength of the
second wave in the copper pipe?
A. ( 1087 mathrm{m} )
в. 0.187 т
c. ( 9.200 m )
D. ( 0.004348 mathrm{m} )
ह. ( 2,300,000 m )
9
170The time taken by a particle in reaching from a trough to its next crest in a transverse wave is
A . ( T / 4 )
B. T/2
c.
D. 3T/4
9
171Fill in the blank.
The time taken by oscillation to
complete is called time period.
A. one
B. Two
c. Three
D. Four
9
172On a slinky, which of the following is
produced?
A. A longitudinal wave but not a transverse wave
B. A transverse wave but not a longitudinal wave
C. A longitudinal wave as well as a transverse wave
D. Neither a longitudinal nor a transverse wave
9
173Sound travels the fastest in which
medium?
A. Gaseous
B. Liquid
c. Solid
D. Vacuum
9
174Sound travels fast in ( _{text {一一一一一一一 }} ) than
liquids
9
175Sound is a form of:
A . heat
B. vibration
c. energy
D. frequency
8
176Give reasons as to why one cannot hear the sound produced by other sources on
the moon.
A. no presence of a medium for propagation
B. the radiations from the sun destroy all the sound waves created
c. sound only propagates on the earth
D. none of these
9
177An ultrasonic source emits sound of
frequency ( 220 k H z ) in air. If this sound
meets a water surface, what is the
wavelength of
(a) the reflected sound,
(b) the transmitted sound? (At the
atmospheric temperature, speed of
sound in air ( =352 m s^{-1} ) and in water
( =1496 m s^{-1} )
9
178What devices are used to locate
underwater objects and to determine
depths of water beneath the ship?
9
179The sound heard after reflection from a
rigid surface is
called
9
180Vibrating bodies produce
A . light
B. sound
c. heat
D. all of the above
8
181Sound can be produced by
A. striking a tuning fork
B. plucking a stretched rubber string
C . flicking a thin ruler
D. all the actions above
8
182What is meant by natural frequency of vibration of a body?9
1
( A )
11
B.
(2)
( c )
( D )
(4)
9
184Assertion
Two persons on the surface of moon
cannot talk to each other
Reason

There is no atmosphere
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

9
185A sonar device on a submarine send out
a signal and receives an echo 5 seconds later. Calculate the speed of sound in water, if the distance of the object from the submarine is ( 3625 mathrm{m} )
A. ( 1440 mathrm{ms}^{1} )
B. ( 1460 mathrm{ms}^{1} )
c. ( 1450 m s^{1} )
D. ( 1470 mathrm{ms}^{1} )
9
Sound can travel through
A. Gases only
B. Solids only
c. Liquids only
D. solids, liquids and gases
9
187Why do musical instruments create
sound on being played?
A. Because they vibrate.
B. Because they have a secret music player in them
c. Both A and B
D. Can’t say
8
188What conclusion can be obtained from
the observation that when the prongs of a sound making tuning fork touch
a beaker, the water gets splashed?
A. that the prongs of tuning fork are vibrating
B. the prongs of tuning fork produce ultrasound
c. waves are produced on the surface of water
D. all the above
8
189The vibrations or the pressure
variations inside the inner ear are
converted into electrical signals by the
A. cochlea
B. tympanic Membrane
c. pinna
D. anvil
9
190How does sound is produced by
humans?
A. In humans sound is produced by the voice box.
B. In humans sound is produced by the larynx.
C. In humans sound is produced by the upper part of the wind pipe.
D. All
8
191An echo is simply a……..of sound.
A. Reflection
B. Frequency
c. Amplitude
D. None of these
9
192A bomb explodes on the moon. How long will it take for the sound to reach the
earth?
A . 10 seconds
B. 1000 seconds
c. 1 day
D. None of these
9
193When sound waves travel from one
medium to another, which of the
following physical quantities does NOT alter?
A. Amplitude
B. Velocity
c. Frequency
D. Intensity
9
194A submarine that is not moving sends out a sonar sound wave travelling at ( 200 mathrm{m} / mathrm{s}, ) which reflects off a boat back
to the submarine. The sonar crew
detects the reflected wave 8 s after it
was send out. how far away is the boat from the submarine?
A. ( 8000 m )
в. ( 80 m )
c. ( 800 m )
D. ( 9000 m )
9
195In which of the following medium speed of the sound is maximum?
A. steel
B. wood
c. water
D. Air
E. Helium
9
196When sound waves travels from air to
water, which of the following parameters remains constant?
A. Wavelength
B. Velocity
c. Frequency
D. Phase
9
197Which body part is useful to make basic sound of the voice in humans?
A. Vocal folds in larynx
B. Lungs
c. wind pipe
D. Throat
8
198When a glass filled with water is struck with a stick, ripples are produced in the water. This indicates that
A. the glass is not vibrating
B. the glass may or may not be vibrating.
c. the glass is vibrating.
D. none of the above is true
8
199Megaphones or loudhailers, horns,
musical instruments such as trumpets
and shehnais, are all designed to
A. send sound in a particular direction without spreading it in all directions.
B. send sound in a particular direction spreading it in all directions.
C. collect sound from all directions spreading it in all directions.
D. all of the above
9
200The sounds having frequency of ( 20 mathrm{Hz} ) to ( 20,000 mathrm{Hz} ) are
A . Ultrasound
B. Infrasonics
c. Hypersonics
D. Audible Sounds
9
201The sounds having frequency less than ( 20 mathrm{Hz} ) are called ultrasonics.
A. True
B. False
9
202The persistence of audible sound due to
the successive reflections from the
surrounding objects even after the source has stopped to produce that sound is
called
A . reflection
B. echo
c. reverberation
D. rarefaction
9
203The children are at opposite ends of metal rod. One strikes the end of the rod
with big pebble. Find the ratio of time
taken by the sound waves in air and in the metal to reach it second child. (Speed in rod ( =6420 mathrm{m} / mathrm{s} ) ).
A . 221.3
B. 18.55
c. 22.13
D. 185.5
9
204From following where all SONAR is used?
A. Measure depth of sea bed
B. Locate scraps
c. locate submarines
D. All of the above
9
205The frequencies below ( 20 mathrm{Hz} ) are known as infrasonic sounds.
A . True
B. False
9
206In SONAR, we use
A. ultrasonic waves
B. infrasonic waves
D. audible sound waves
9
207The voices of men, women and children are different due to difference in:
A. larynx
B. lungs
c. vocal coards
D. wind pipe
8
208A man stands between two cliffs and
fires a gun. He hears two successive
echoes after 3 s and 5 s. Find the
distance between the two cliffs?
9
209A bomb explodes on the moon. How long will it take for the sound to reach the
earth?
( mathbf{A} cdot 10 sec )
B. 1000sec
c. ( 1 d a y )
D. None of these
9
210When we hear a sound, we can identify
it source from
A. The frequency of the sound
B. The amplitude of the soundd
c. The wavelength of the sound
D. The overtones present in the sound
8
211Match column I with column II.9
212The speed of sound in air is ( 5100 mathrm{m} / mathrm{s} ) True or false.
A . True
B. False
9
213In which of three media; air, water and steel, does sound travel the fastest?
A . air
B. water
c. steel
D. none of these
9
214Reverberation of sound is due to
A. multiple refractions
B. multiple reflections
C . multiple diffractions
D. multiple polarization
9
215Human ear is divided into:
A. external ear
B. middle ear
c. inner ear
D. all
9
216A man produce sound with trumpet. A wave has a wavelength of ( 8.75 mathrm{mm} ) and frequency of ( 40 mathrm{kHz} ). If the man receives an echo after reflecting from the wall 0.4 s later. Calculate the distance between
man and the wall.
( A cdot 35 mathrm{m} )
B. 70
c. ( 105 mathrm{m} )
D. ( 140 mathrm{m} )
E. ( 175 mathrm{m} )
9
217Assertion
Every vibrating body is a source of
Sound.
Reason
All sounds are audible.
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
8
218What is the process, of converting the air pressure from lungs into audible vibrations, called?
A. Excitation
B. Vibration
c. Phonation
D. None
8
219How many inner and outer hair cells
does a normal human ear possess?
A . 25000
B. 30000
c. 27000
D. 50000
9
220Peak of the density/pressure distance curve represents:
A. maximum rarefaction
B. maximum compression
c. minimum compression
D. minimum rarefacton
9
221An ultrasonic wave is sent from a ship towards the bottom of the sea. It is
found that the time interval between the
sending and receiving of the wave is 1.6
s. What is the depth of the sea, if the velocity of sound in the seawater is ( 1400 mathrm{m} / mathrm{s} ? )
A. ( 1120 mathrm{m} )
B. 560 ( m )
( c cdot 1400 m )
D. 112 m
9
222Speed of sound waves in fluid is
A. directly proportional to the square root of bulk modulus of the medium.
B. inversely proportional to the bulk modulus of the medium
C. directly proportional to the density of the medium.
D. inversely proportional to the density of the medium.
9
223A person standing symmetrically between two cliffs claps his hands and starts hearing series of echoes at intervals of 1 sec. If speed of sound in air is ( 340 mathrm{m} / mathrm{s} ), the distance between the parallel cliff must be
A. 340 ( m )
B. 680 ( m )
c. ( 1020 mathrm{m} )
D. ( 170 mathrm{m} )
9
2241 Hz is:
A. 1 vibration per minute.
B. 360 vibration per minute.
C . 10 vibration per minute.
D. 60 vibration per minute.
9
225Three different vibrating bodies produce three types of the sounds ( X ), Y and ( Z ) Sounds ( X ) and ( Y ) cannot be hear by a man
having normal range of hearing but sound ( z ) can be heard easily.The sound ( x ) is used to find faults and cracks in
metals.The sound similar to that which is
produced during an earthquake before the main shock wave is generated. Name one device which can produce sound like
( X )
A. megaphone
B. sonar
c. bulb horn
D. ear mufflers
9
226What stimulates the auditory nerve?
A. The movement of the three ear ossicles
B. The movement of stirrup
C. The movement of fluid in the cochlea
D. All of these
9
227Which of following can not travel through vacuum?
A. Electromagnetic wave
B. Sound wave
c. Light wave
D. X-ray
9
228A road runs parallel to a vertical cliff at a distance of ( 680 mathrm{m} ) as shown in the
figure. A truck, standing at ( P ) sounded the horn at an instance and the truck
driver hears the echo after ( 4 s ). But the
sound of the horn was heard twice by a
person standing at ( Q ) within an interval
of ( 2 s . ) Give reasons why the person at ( Q ) heard the sound twice. Neglecting the wind velocity. Calculate how far the person was from the truck?
9
229The sound of the human voice is
produced due to
A. movement of tongue
B. vibration in the pharynx
c. vibration in the vocal cord
D. vibration below tongue
8
230A pendulum oscillates 40 times in 4 seconds. Find its time period and frequency.9
231Two children are at opposite ends of an iron pipe. One strikes his end of the iron pipe with a stone. Find the ratio of times taken by the sound wave in air and in iron to reach the other child. Given,
velocity of sound in air is ( 344 mathrm{m} s^{-1} ) and that in iron is ( 5130 m s^{-1} )
A ( frac{t_{1}}{t_{2}}=14.3 )
в. ( frac{t_{1}}{t_{2}}=11.9 )
c. ( frac{t_{1}}{t_{2}}=14.9 )
D. ( frac{t_{1}}{t_{2}}=10.4 )
9
232Imagine a cannon being fired on the
surface of the moon. Then
A. the sound will be heard at the surface of the earth during all seasons
B. the sound will not be heard at the surface of the earth
c. the sound will be heard at the surface of the earth during the rainy season
D. no sound will be heard on the earth or on the moon
9
233A material medium is not necessary for the propagation of sound. State true or false.
A. True
B. False
9
234The frequency of a wave is 5 Hz. Then the wave is a/an (type of wave)
A . ultrasonic wave
B. microwaves wave
c. infrasonics wave
9
235How the waves are analysed in water
with the help of computer?
A. Ultrasonic waves return after reflection from anything in the water
B. Infrasonic waves return after reflection from anything in the water
C. Ultrasonic waves never return after reflection from anything in the water
D. Ultrasonic waves return after refraction from anything in the water
9
236Assertion – the basic pf Laplace correction was that, exchange of heat between the region of compression and rarefraction in air is not possible. reason – Air is a bad conductor of heat
and velocity of sound in air is large.
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
9
237How do bats locate their prey? Explain in detail.9
238Not all kinds of vibration in the material
bodies produce sensation of sound. True or false
A. True
B. False
8
239Three small interlocking bones: the hammer, the anvil, and the stirrup transmit the vibrations of the eardrum
to the inner ear.
A. True
B. False
c. Ambiguous
D. Data insufficient
9
240Sound cannot travel through
A. vacuum
B. solids
c. liquids
D. gases
9
241How is it possible to detect the filling of a bottle under a water tap by hearing the sound at a distance?9
242The frequency of a source is ( 20 mathrm{kHz} ). The frequencies of sound wave produced by it in water and air will be :
A. Same as that of source ( simeq 20 mathrm{kHz} )
B . > 20 kHz
( mathrm{c} .<20 mathrm{kHz} )
D. Depends upon velocity
9
243Sound waves can’t be Polaroids.
Explain:
9
244S.I unit of intensity of sound is
A cdot joule ( s^{-1} m^{-2} )
B. watt ( m^{-2} )
c. joule/s/m ( ^{2} )
D. all
9
245Which of the following waves do not require any kind of medium to
propagate?
A. Sound
B. Earthquake Waves
c. Light waves
D. water surface waves
9
246Elephants communicate with
A. Sonic sound
B. Infrasonic sound
c. Ultrasonic sound
D. None of these
9
247The sound waves which cannot be heard
by a human ear are called.
A. Ultrasonic sounds
B. Infrasonic sounds
c. Extraordinary sounds
D. Both (a) and (c)
8
248Identify in which of the following medium, a sound wave would travel with fastest speed.
A. solid
B. liquid
c. gas
D. vacuum
E. plasma
9
249What all properties are detected on
basis of speed and nature of reflected
ultrasound waves?
A. Shape and position of object
B. Shape and height of object
c. shape and size of object
D. weight and position of object
9
250With the help of the given clues, unscramble the letters to make a
meaningful word. HCEO (A reflected sound wave)
9
251The frequency of a sound wave is 200 ( mathrm{Hz} ) and its wavelength is ( 150 mathrm{cm} . ) What is the distance travelled by a sound wave in the time of produce 150 waves?
A . ( 110.5 mathrm{m} )
B. 112.5 ( m )
c. ( 115 mathrm{m} )
D. 120 ( m )
9
252What is the name of the strings which vibrate in our voice box when we talk?
A. Oesophagus
B. Pharyngeal slits
c. vocal cords
D. None of these
8
253The time period of a sound wave from a piano is ( 1.18 times 10^{-3} s . ) Find its
frequency
( mathbf{A} cdot 847.45 H z )
в. ( 800 H z )
( mathbf{c} .935 .55 H z )
D. ( 1000 H z )
9
254If the ceiling of a cinema is made flat,
what will happen?
A. No sound will be audible at all
B. Picture will vanish
c. Sound will not reach properly to every person
D. Pictures will not be clear to everyone
9
255When sound travel from air to water
which one of the following remains constant?
A. Time period
B. Frequency
c. velocity
D. wavelength
9
256How does sound from a sound
producing body travel through air to
reach our ears?
A. through crest and troughs
B. through compression and rarefaction
( c cdot ) both
D. none
9
257Suppose you hear music being played from a trumpet that is across the room from you. Compressions and rarefaction
from the sound wave reach your car, and you interpret these vibrations as
sound. Were the air particles that are vibrating near your ear carried across the room by the sound wave? How do you know?
9
258A body produces sound only if it
is
c. plucked
D. vibrating
8
259Reflected sound waves are called9
260State whether given statement is True or False

In humans, sound is produced because of the vibration of the larynx.
A. True
B. False

8
261Define echo.9
262Function of ear bones is to
A. stabilize the ear
B. maintain the pressure
C. magnify the force of vibration
D. do none of these
9
263The diagram below shows the different
modes of vibration ( P, Q ) and ( R ) of the same string of a given length
(a) Which vibration will produce a louder sound and why?
(b) Which vibration will produce the sound of maximum shrillness (or pitch)
and why?
(c) What is the ratio of the wavelength of vibrations P and R?
9
264What is the name of the strings which vibrate in our voice box when we talk?
A. oesophagus
B. pharyngeal slits
c. vocal cords
D. all
8
265A pressure of ( 100 k P a ) causes a decrease in volume of water by
( 5 times 10^{-3} ) percent. The speed of sound in water is
A ( cdot ) १४१४ ( m s^{-1} )
B. ( 1000 mathrm{ms}^{-1} )
c. ( 2000 mathrm{ms}^{-1} )
D. 3000 ( m s^{-1} )
9
266Do you hear the sound when bell jar is completely evacuated?9
267Sound travels the fastest in which of the
following mediums?
A. water
B. steel
c. Air
D. Kerosene oil
9
268Explain the working and application of a
sonar
9
269If a musical instrument is played on very high pitch then its frequency is:
A. same
B. highh
c. low
D. zero
9
270A person is in front of a vertical
mountain fires a bullet and hears its
echo after a time 6 s. The person walks a
distance d towards mountain then fires
another bullet and hears its echo after a
time 2 s. If velocity of sound in air is 340
( mathrm{ms}^{-1} . ) The value of d is
A. 340 ( m )
B. 170 ( m )
c. ( 255 mathrm{m} )
D. ( 680 mathrm{m} )
9
271The frequency of ( B ) is ( 3 % ) greater than ( A )
The frequency of ( C ) is ( 2 % ) less than that
of ( A, ) if ( B ) and ( C ) produce 8 beats ( / s, ) then the frequency of ( boldsymbol{A} ) is
9
272The frequencies of four sound waves are given below. Which of these sound
waves can be used to measure the
depth of sea by the echo method?
( A cdot 15,000 mathrm{Hz} )
B. 10 kHz
c. ( 50 mathrm{kHz} )
D. ( 10,000 mathrm{Hz} )
9
273Assertion
The frequency of a sound wave changes
as it travels from one medium to
another medium.
Reason
The velocity of the wave changes as well
as the wavelength if the medium
changes.
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
9
274Echo is a type of
A. Reflected sound
B. Refracted sound
C. Neither reflected nor refracted sound
D. None of these
9
275Sound waves of frequency ( 600 mathrm{Hz} ) fall normally on perfectly reflecting wall. The distance from the wall at which the air
particles have the maximum amplitude of vibration is
(speed of sound in air ( =330 mathrm{m} / mathrm{s} ) )
( A cdot 13.75 mathrm{cm} )
B. ( 40.25 mathrm{cm} )
( c .70 .5 mathrm{cm} )
D. ( 60.75 mathrm{cm} )
9
276Two sources of sound ( S_{1} ) and ( S_{2} )
produce sound waves of same frequency ( 660 H z . ) A listener is moving
from source ( S_{1} ) towards ( S_{2} ) with a
constant speed ( u ) m/ ( s ) and he hears
10 beats/s. The velocity of sound is
( 330 m / s . ) Then, ( u ) equals:
A ( .2 .5 mathrm{m} / mathrm{s} )
в. ( 15.0 mathrm{m} / mathrm{s} )
( c .5 .5 m / s )
D. ( 10.0 mathrm{m} / mathrm{s} )
9
277Voice of which of the following creatures is likely to have maximum frequency?
A. Man
B. cow
c. Bird
( D cdot operatorname{Dog} )
9
278If the velocity of sound in a gas is 360 ( mathrm{m} / mathrm{s} ) and the distance between
compression and the nearest rarefraction is ( 1 mathrm{m} ), then the frequency of sound is
( A cdot 90 mathrm{Hz} )
в. 180 Н ( z )
c. 360 нz
D. 720 нz
9
279The audible range in humans is
( mathbf{A} cdot 20 H z ) to ( 2000 H z )
B. ( 200 H z ) to ( 20,000 H z )
c. ( 20 H z ) to ( 20,000 H z )
D. ( 200 H z ) to ( 20 k H z )
9
280When we say’sound travels in a
medium’ we mean:
A. the particles of the medium travel
B. the source travels
c. the disturbance travels
D. the medium travels
9
281As the temperature of the medium increases,
A. speed of sound increases
B. speed of sound decreases
c. no effect on speed of sound
D. may increase or decrease
9
282When a flute is blown, the air inside it
gets compressed and produces sound but does not vibrate. True or false.
A. True
B. False
8
283A plane wave of sound traveling in air is incident upon a plane water surface. The angle of incidence is ( 60^{circ} . ) Assuming
Snell’s law to be valid for sound, it follows that the sound wave will be
refracted into the water away from the normal.
A. True
B. False
9
284Which of the following voices is likely to have minimum frequency?
A. Baby girl
B. Baby boy
c. A man
D. A woman
8
285With the help of the given clues, unscramble the letters to make a
meaningful word. ETHZR (unit of frequency of sound wave)
9
286Human ears can sense sound wave
travelling in air having wavelength of
A ( cdot 10^{-3} mathrm{m} )
B. ( 10^{-2} mathrm{m} )
( c cdot 1 m )
D. ( 10^{2} mathrm{m} )
9
287Percussion instruments are musical
instruments that are played by
A. banging
B. shaking
c. both A and B
D. hitting
8
288Why is the speed of sound different in
different media?
9
289Where is the voice box located in the
body?
A. At the upper end of the windpipe
B. At the upper end of the lungs
c. At the lower end of the windpipe
D. In between the oesophagus
8
290State whether given statement is True
or False

It is usually preferable to have a longer reverberation time in an auditorium for
music than one for speeches.
A. True
B. False

9
291Which of the above two graphs (a) and
(b) representing the human voice is
likely to be the male voice ? Give a
( A )
B. B
( c cdot c )
( D )
8
292Frequency of vibration of a particle is 10
Hz. If the amplitude of vibration is doubled, what will be the change in frequency of vibration
A. frequency doubles
B. frequency becomes halved
c. frequency remains same
9
293Fix up one end of a slinky to a hook and hold it horizontally. Vibrate the other end to and fro along the length of the spring. If you look the spring carefully, you will see some parts of the spring are pushed closer, while some other
parts are pulled apart.
A. the portions which are pushed closer are called compressions
B. the portions which are pulled apart are called rarefactions
c. both a and ( b )
D. none
9
294Two open pipes of length ( 25 mathrm{cm} ) and 25.5 cm produced 10 beat/second. The velocity of sound will be:
A. ( 255 mathrm{m} / mathrm{s} )
B. 250 m/s
c. ( 350 mathrm{m} / mathrm{s} )
D. None of these
9
295How is sound produced and how is it transmitted and heard by us?8
296A man who is standing at a point ( x ) between two parallel walls as shown in the diagram, fires a starting pistol. He hears the first echo after 0.6 s and
another one after ( 0 . ) s.

How long after firing the pistol will he hear the next echo?
A ( .1 .2 mathrm{s} )
B . 1.4
( c cdot 1.6 s )
D. 2.4 s

9
297Sound wave in air are
waves.
A. longitudinal
c. transverse
D. electromagnetic
8
298Imagine a cannon being fired on the
surface of the moon. Then the sound will
This question has multiple correct options
A. Be heard at the surface of the earth during all seasons
B. Not be heard at the surface of the earth
( mathrm{C} . ) Be heard at the surface of the earth during the rainy season
D. Not be heard on the earth or on the moon
9
299What is sound and how is it produced?8
300State the use of echo by a bat, dolphin and fisherman.9
301A man stands in front of a hill rock and
fires a gun. He hears an echo after 1.5 sec. The distance of the hill rock from
the man is (velocity of sound in
air=330m/s)
A . 220m
B. 247.5m
( c .268 .5 mathrm{m} )
D. 292.5m
9
302A boy stands ( 85 mathrm{m} ) infront of a high wall and then blows a whistle. Calculate the
time interval when he hears an echo.
(speed of sound ( =340 m s^{-1} ) )
A . ( 0.1 mathrm{s} )
B. ( 0.2 mathrm{s} )
c. ( 0.5 mathrm{s} )
D. 1 s
9
303Match The following:
begin{tabular}{ll|l|l}
& Column-1 & & Column-2 \
hline ( mathrm{A} ) & Audible range & ( mathrm{p} ) & Faster transmission of sound \
hline ( mathrm{B} ) & Infrasonic range & ( mathrm{q} ) & Slower transmission of sound \
hline ( mathrm{C} ) & Ultrasonic range & ( mathrm{r} ) & Less than ( 20 mathrm{Hz} ) \
( mathrm{E} ) & Denser medium & ( mathrm{s} ) & ( 20 mathrm{Hz}-20 mathrm{kHz} ) \
& & & \
Rarer medium & ( mathrm{t} ) & More than ( 20 mathrm{kHz} )
end{tabular}
9
304A person is in between two vertical
mountains. The person fires a gun then hears the first echo from the nearby mountain in a time 3 s and
hears second echo from far mountain in
a time 4s. The person hears the third echo after
A . 5 s
B. 6 s
( c cdot 7 s )
( D cdot 8 s )
9
305The reverberation times in a cinema
theatre are ( 3 s, 2 s ) when it is empty,
filled with audience respectively. The
reverberation time when the theatre is
half filled with audience is
A . 2.3 s
B. 2.4
( c .2 .5 mathrm{s} )
D. 2.6 s
9
306Name the waves which are used in
‘SONAR’ to find the depth of a sea. State
one property of waves for their use.
9
307Choose the correct statements (s) from
the following?
This question has multiple correct options
A. Mechanical waves need medium for their propogation
B. Sound cannot travel through vaccum
C. Mechanical waves transport energy from one place to another
D. Sound waves are non mechanical waves
9
308The frequency of sound waves can be
expressed in
A . ( mathrm{Hz} )
B. Cycles
( c cdot s^{-1} )
D. All of these
9
309An echo is heard, if between the source and the reflector is
atleast ( 17 mathrm{m} )
A. time
B. distance
c. arc length
D. none of these
9
310Echo is a type of
A. Reflected sound
B. Refracted sound
C. Neither reflected sound nor refracted sound
D. None of these
9
311Assertion
Echo is produced only when sound is incident on hard and polished surface
Reason

Sound energy can be totally reflected by objects with soft and loose texture
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

9
312State whether given statement is True or False

Light waves require no medium for their propagation.
A. True
B. False

9
313Assertion
Ultrasonic waves are longitudinal waves of frequency grater than ( 20,000 H z )
Reason
The maximum frequency of audible sound waves is ( 20,000 H z )
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
9
314If speed of infrasonics, audible and
ultrasonics waves are ( v_{i}, v_{a} ) and ( v_{u} ) then
A ( cdot v_{i}>v_{a}>v_{u} )
В . ( v_{i}=v_{a}=v_{u} )
c. ( v_{i}<v_{a}v_{a}, v_{u}>v_{a} )
9
315An echo will be heard if the minimum
distance between the source of sound
and the obstacle is
A. ( 1 mathrm{m} )
B. 10
( c cdot 15 m )
D. 17 m
9
316A particle vibrates 10 times in 1 sec. What is the time period of vibration of
the particle
A . ( 10 mathrm{Sec} )
B. 1 Sec
c. ( 0.1 mathrm{sec} )
D. 0.01 sec
9
317Fill in the blank.
Vibrations inside the ear are amplified by the three bones namely the in
the middle ear
A. Hammer, anvil and stirrup
B. Hammer, Anvil and pinna
c. Hammer, cochlea and stirrup
D. Auditory bone, anvil and stirrup
9
318A boy who resides near a powerloom has
developed a habit of speaking loudly everywhere. Give a scientific reason.
9
319A sound wave has a frequency of ( 192 mathrm{Hz} ) and travels the length of a football field, ( 91.4 mathrm{m}, ) in ( 0.27 mathrm{s} . ) What is the speed of the wave?
A. ( 338.5 mathrm{m} / mathrm{s} )
В. ( 348.5 mathrm{m} / mathrm{s} )
c. ( 358.5 mathrm{m} / mathrm{s} )
D. ( 368.5 mathrm{m} / mathrm{s} )
9
320(A). The reverberation time is
dependent on the shape of the enclosure, position of the sources and observer.
(B) The unit of absorption coefficient in
S.I. system in metric is sabine
A. both (A) and (B) are true
B. both (A) and (B) are false
c. (A) is true but (B) is false
D. (A) is false but (B) is true
9
321The sound waves starts vibrating when
it reaches:
A. pinna
B. stirrup
c. tympanic membrane
D. all
9
322What type of wave is represented by displacement-distance graph?
A . Longitudinal wave
B. Transverse wave
c. sound waves
D. water waves
9
Sound can travel through
A. Gases only
B. Solids only
c. Liquids only
D. solids, liquids and gases
9
324Sound travels faster in gases when compared to solids and liquids.9
325State whether true or false.
The other name for the voice box in
humans is Larynx.
A. True
B. False
8
326Find the ratio of speed of sound in
hydrogen to the speed of sound in
oxygen at ( 1270 K )
9
327Two people can hear the sound of each
other on the moon’s surface.
A. True
B. False
9
328A person carrying a whistle emitting
continuously a note of ( 272 H z ) is running towards a reflecting surface with a speed of ( 18 k m / )hour. speed of
sound in air is ( 45 m / s . ) The number of
beats heard by him is:
A . 4
B. 6
( c cdot 8 )
( D cdot 3 )
9
329Assertion
Sound waves cannot pass through
vacuum.
Reason
Sound waves are mechanical waves,
which require a medium for their
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. Assertion is incorrect but Reason is correct
9
330Longitudinal waves travels faster in
which medium:
A . liquids
B. gases
c. solids
D. vacuum
9
331SONAR works on the principle of:
A. Reflection of sound waves
B. Momentum of sound waves
C. Energy of sound waves
D. Refraction of sound waves
9
332In the bell jar experiment, after starting the vacuum pump the sound gradually become fainter and finally we hear a feeble sound. Why?
A. The Vacuum pump absorbs the sound
B. The medium is sucked by the pump
c. The bell jar behaves as isolated medium
D. The bell do not produce such strong sound as it was producing earlier
9
333The phenomenon of echo of sound waves is due to:
A. Reflection
B. Interference
c. Diffraction
D. All of the above
9
334Assertion
Statement-1: Echo is produced when
sound is incident on hard and polished
surface.
Reason
Statement-2: Sound energy can be totally reflected by objects with soft and loose texture.
A. Both Statements-1 and 2 are true and Statement-2 is the correct explanation of Statement- 1
B. Both Statements-1 and 2 are true but Statement-2 is not the correct explanation of Statement- 1
c. Statement-1 is true and Statement-2 is false
D. Both Statements-1 and 2 are false
9
335Reverberation time of a hall used for
speeches should be very short. Why?
A. Multiple echos will enhance the sound quality.
B. Multiple echos will interfere with the original sound
c. Both a and 6
D. None of the above
9
336Sound travels the fastest through vacuum. State whether true or false.
A. True
B. False
9
337The property of ultrasonic waves used in manufacturing emulsion for photographic films is its,
A. High speed
B. High frequency
c. Higher wavelength
D. High amplitude
9
338Medium is necessary for sound to propagate.
A . True
B. False
9
339The grandparents and parents of twoyear old girl are playing with her in a room. A sound source produces a ( 28 k H z ) sound. Who in the room is most
likely to hear the sound?
A. Grandparent
B. Little girl
c. Both
D. None of them
9
340Perforated card boards are used in
halls, for
A. reflection of sound
B. absorption of sound
c. refraction of sound
D. as a decorative materia
9
341The audible frequency for a normal human being is ( 20 mathrm{Hz} ) to ( 20 mathrm{kHz} ). Find
the corresponding wavelengths if the speed of sound in air ( 320 mathrm{m} / mathrm{s} )
9
342A boy fires a gun and another boy at a distance hears the sound of fire 2.5 s
after seeing the flash. If speed of sound
in air is ( 340 m s^{-1}, ) find the distance
between the boys:
( mathbf{A} .850 m )
в. 8500 т
c. ( 1700 m )
D. none of the above
9
343SONAR is
B. SOund Nullyfying And Ranging
C. SOund Navigation with Amplitude and Ranging
D. None
9
344(1) The reflected pulse will be in same orientation of incident pulse due to a
phase change of ( pi ) radians.
(2) During reflection the wall exerts a force on string in upward direction. For the above given two statements choose the correct option given below.
A. Only (1) is true
B. Only (2) is true
c. Both are true
D. Both are wrong
9
345A stationary source emits sound of
frequency ( f_{0}=492 H z . ) The sound is
reflected by a large car approaching the
source with a speed of ( 2 m s^{-1} ). The
reflected signal is received by the source and superposed with the original. What will be the beat frequency of the resulting signal in ( H z ? ) (Given that the speed of sound in air is ( 330 m s^{-1} ) and the car reflects the sound
at the frequency it has received)
9
346SONAR can be used
A. for determination of a depth of a sea
B. in the ships to locate underwater rocks, icebergs
C. to measure distance, direction and speed of underwater objects, such as hills,valleys etc
D. for all the above
9
347What is the effect of humidity on quality of sounds propagation? Is there any difference in propagation of sound in air during the summer and winter seasons? Discuss9
348Which is not true for a wave?
A. Wave velocity ( v=n lambda )
B. Energy is transferred during wave motion
C. All waves can pass through vacuum
D. Unit of wave velocity is ( m / s )
9
349An audible sound has the frequency
range of
9
350If we tighten the stretched strings of guitar, then pitch will be
A. lower
B. higher
c. same
D. dependent upon size of instrument
8
351The persistence of hearing of human beings is not more than
A . ( 1 mathrm{s} )
в. ( frac{1}{5} ) s
c. ( frac{1}{10} ) s
D. ( frac{1}{2} ) s
9
352A very loud sound
A. damages the hair cells of the inner ear
B. damages the outer ear
C . damages the middle ear
D. reflects back from the ear
9
353The sounds having frequency less than
( 20 H z ) are called ultrasonics. True or
False?
9
354Which of the following can travel through vacuum?

This question has multiple correct options
A . Light waves
B. Heat waves
c. ( x ) -rays
D. sound waves

9
355A pulse is a wave:
A. Of high duration
B. Of short duration
C. Which travels in vacuum only
D. Which travels in solids only
9
356Ultrasonics are useful for.
A. Bats only
B. Human beings only
C. Bats and human beings
D. Neither bats nor human beings
9
357How does the sound produced by a vibrating object in a medium reach
A. Through electron transfer
B. Through the vibration of particles
c. Sound waves don’t need a medium
D. Not enough data
9
358Vocal cords in men are about
long.
A. 20 mm
B. 20 cm
( c cdot 20 m )
D. ( 15 mathrm{cm} )
8
359In resonance column experiment, the velocity of sound is given by ( v= ) ( 2 nleft(l_{2}-l_{1}right) . ) Where ( n ) is frequency ( =325 )
Hz measured accurately. ( l_{1}, l_{2} ) are
resonating length and are measured as ( l_{1}=25.0 c m, l_{2}=75.0 c m ) then speed of
sound is
A. ( 350 m / s )
в. ( 327 m / s )
c. ( 325 m / s )
D. ( 400 mathrm{m} / mathrm{s} )
9
360A stone is dropped in a well of depth 500
( mathrm{m} ) and a sound is heard after ( 80 / 7 )
seconds. Then speed of sound is: ( [boldsymbol{g}= )
( left.mathbf{1 0 m} / boldsymbol{s}^{mathbf{2}}right] )
A. ( 300 mathrm{m} / mathrm{s} )
B. ( 350 mathrm{m} / mathrm{s} )
c. ( 400 mathrm{m} / mathrm{s} )
D. ( 330 mathrm{m} / mathrm{s} )
9
361Sound can travel through
A. solids and liquids
B. liquids and gases
c. solids and gases
D. all of these
9
362The energy per unit area associated
with a progressive sound wave will be doubled if:
A. The amplitude of the wave is doubled
B. The amplitude of the wave is increased by ( 50 % )
C. The amplitude of the wave is increased by ( 41 % )
D. The frequency of the wave is increased by 50%
9
363Reverberations in a room is minimized
by
A. talking softly
B. using an extra layer of paint
c. use of curtains
D. none of the above
9
364Sound from the outside world reach the
inner ear through:
A. pinna
B. cochlea
c. auditory canal
D. labyrinth
9
365Velocity of sound is maximum in
A . solids
B. liquids
c. ( g )ases
D. ionized gases
9
366When the sound waves reach the
it starts vibrating:
A. pinna
B. stir rup
C . tympanic membrane
D. none of these
9
367With the help of the given clues, unscramble the letters to make a
meaningful word. RAYXLN (produces sound in humans)
8
368A sound signal is simultaneously sent in air and water from a boat on a river.
The echo of sound striked by river bed is heard in ( 4 s, ) while echo striked by aeroplane is heard in ( 8 s ). Find the distance between aeroplane and river
bed.
[velocity of sound in air ( =350 m / s )
velocity of sound in water ( =1500 m / s] )
A. ( 4.4 k m )
B. ( 6.4 k m )
c. ( 8.8 k m )
D. ( 13.4 k m )
9
369Which instrument is used to measure
depth of ocean?
A. Galvanometer
B. Fluxmeter
c. Endoscope
D. Fathometer
9
370Sound travels faster in gases as compared to solids and liquids.
A. True
B. False
9
371A particle performs 20 vibrations in 5 secs. The time period of vibration is
A . 2.5
B. ( 0.1 mathrm{s} )
c. ( 0.25 mathrm{s} )
( D cdot 4 s )
9
372Which of the following type of waves is used in the SONAR device?
B. audible sound waves
c. infrasonic waves
D. ultrasonic waves
9
373The device used to measure the
distance and direction of underwater
substances using ultrasonic waves is
9
374A police car with a siren of frequency ( 8 k H z ) is moving with uniform velocity ( 36 k m / h r ) towards a tall building which reflects the sound waves. The speed of sound in air is ( 320 m / s . ) The frequency
of the siren heard by the car driver is:
A. ( 8.50 k H z )
B. ( 8.25 k H z )
c. ( 7.75 k H z )
D. ( 7.50 k H z )
9
375In a transverse wave the distance
between a crest and neighbouring trough at the same instant is ( 4.0 mathrm{cm} ) and the distance between a crest and
trough at the same place is ( 1.0 mathrm{cm} . ) The next crest appears at the same place after a time interval of 0.4 s. The
maximum speed of the vibrating
particles in the medium is:
A ( cdot frac{5 pi}{2} mathrm{cm} / mathrm{s} )
B. ( 2 pi c m / s )
c. ( frac{pi}{2} mathrm{cm} / mathrm{s} )
D. ( frac{3 pi}{2} mathrm{cm} / mathrm{s} )
9
376Describe an activity to show that sound is produced by vibration of materials.8
377Choose the correct statement(s) from
the following?
This question has multiple correct options
A. Mechanical waves need medium for their propagation.
B. Sound cannot travel through vacuum.
C. Mechanical waves transport energy from one place to another
D. Sound waves are non mechanical waves.
9
378A sonar device on a submarine sends
out a signal and receives an echo 5 s
later. Calculate the speed of sound in water if the distance of the object from the submarine is ( 3625 mathrm{m} )
9
379When the observer and reflector are at
rest, the echo and the original sound differ in
A. Frequency
B. Wavelength
c. velocity
D. Intensity of sound
9
380The ultrasonic waves produced in SONAR is of frequency
A. ( 60,000 mathrm{Hz} )
B. 50,000Hz
c. ( 20,000 mathrm{Hz} )
D. All
9
381Which of the following is independent of the remaining three for a sound wave?
A. Frequency
B. wavelength
c. velocity
D. Amplitude
8
382State whether given statement is True or False
Sonar make use of ultrasound.
A. True
B. False
9
383In humans, the sound is produced by:
A . larynx
B. wind pipe
c. vocal cords
D. lungs
8
384A pulse of sound is produced at the
bottom of a boat. The sound travels
through the water and is
reflected from the sea-bed. The sound
reaches the boat again after 1.3 s. The
sea-bed is ( 1000 m ) below the boat
Using this information, what is the speed of sound in the water?
A. ( 769 mathrm{m} / mathrm{s} )
в. ( 1300 mathrm{m} / mathrm{s} )
c. ( 1538 mathrm{m} / mathrm{s} )
D. ( 2600 mathrm{m} / mathrm{s} )
9
385State whether the following statement
is true or False:

Human beings and most animals like birds, beer, bees, mosquitoes produce sound by the vibrations of their vocal chords.
A. True
B. False

8
386A small bee produces sound, while it moves. The sound is created due to
A. Grinding its teeth as it moves
B. Friction due to air
c. Flapping of wings
D. Sound due to its vocal chord
8
387A vibrating body:
A. Will always produce sound
B. May or may not produce sound if the amplitude of vibration is low
C. Will produce sound which is audible to humans.
D. None of the above
8
388When we go from solid to gaseous state, the speed of sound
A. increases
B. increases or decreases
c. decreases
D. constant
9
389Select the instrument that works on the
principle of multiple reflection of sound.
A. Watthour meter
B. Sonar
c. stethoscope
D. Decibel meter
9
390Assertion
Every vibrating body is a source of
Sound
Reason
All sounds are audible
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
8
391The other name for larynx is
A. voice processor
B. voice modulator
c. voice box
D. voice generator
8
392Which of the following statements
support the fact that sound requires a
material medium to pass through?
A. We do not hear the sound of explosions occurring in Sun
B. Rings of an electric bell put within a vacuumized jar can not be heard
C. If we put one ear on an iron rod and hit on it, we hear two sounds simultanneously
D. All of these
9
393Calculate the ratio of the speed of sound in neon to that in water vapour at any temperature. Given that molecular
weight of neon gas ( =2.02 times )
( 10^{-2} k g m o l e^{-1} ) and molecular weight of
watervapour ( =1.8 times 10^{-2} ) kgmole ( ^{-1} )
A .0 .944
B. 1.944
c. 2.944
D. 3.944
9
394The echo will be heard if the orginal
sound reflected by an obstacle reaches our ears after
A . 10 sec
B. 5 sec
c. 1 sec
D. 0.1 sec
9
395In Dholak sound produce due to which of the following?
A. Stretched membrane
B. Stretched strings
c. Vibration of air
D. Air column
8
396SONAR emits which of the following
waves?
B. Micro waves
c. Ultrasonic waves
D. Gamma rays
9
397Why do we not hear the screams of a bat
A. screams are below ( 30,000 mathrm{Hz} )
B. the screams are infra sonic
C. the screams are ultra sonic
D. all
9
398Which help us to recognize sound?8
399Birds produce sound by using:
A. vocal chord
B. larynx
c. glottis
D. syrinx
8
400The time period of a vibrating body is
0.01 sec. Its frequency will be :
A ( cdot 1.0 s^{-1} )
B. ( 10.0 s^{-1} )
c. ( 100.0 s^{-1} )
D. ( 1000.0 s^{-1} )
9
401A ship sends a longitudinal wave towards the bottom of the sea. The wave
returns from the bottom of the sea after
( mathbf{2 . 0} s . ) The bulk modulus of the sea water
is ( 2.2 times 10^{9} N m^{-2} ) and the density of
water is ( 1.1 mathrm{g} mathrm{cm}^{-3} . ) The depth of the sea is about
A . ( 2200 m )
в. 2000 ( m )
c. ( 1400 m )
D. ( 1100 m )
9
402A metallic spoon falls on a metal plate making a huge sound and upon bouncing from the plate, it falls on to the pile of sand below it with no noise being heard. Sound is not heard on sand because
A. Sound is absorbed by sand particles
B. Sound generated by the plate is more than the sand particles
c. Vibration of metal plate is more than sand particles
D. sand does not vibrate
8
403The compressions and rarefactions are
transmitted across the middle ear
through
A. auditory tube
B. ear ossicles
c. cochlea
D. all of these
9
404Sounds having frequency more than ( 20,000 mathrm{Hz} ) are called –
A. sonic sound
B. ultrasonic sound
c. infrasonic sound
D. none of these
9
405A sonar echo takes ( 4.4 s ) to return from a
submarine. If the speed of sound in
water is ( 1500 m s^{-1}, ) then the distance of submarine from the sonar is:
A ( .1500 m )
в. ( 3000 m )
c. ( 3300 m )
D. 3600m
9
406Vibrations in a body produces sound. How do you prove it?8
407Cite an experiment to show that sound
needs a material medium for its
propagation:
9
408A violin string emits sound of frequency ( 510 H z . ) How far will the sound waves
reach when string complete 250 vibrations? The velocity of sound is ( 340 m / s )
A. ( 166.7 mathrm{m} )
B . 366.7 m.
c. ( 266.7 mathrm{m} )
D. ( 566.7 m )
9
409Every source of sound has to be a
body
A. vibrating
B. resting
c. climbing
D. elastic
8
410State whether given statement is True
or False:

Sound travels faster in vacuum than in
air.
A. True
B. False

9
411The ticking of a watch sounds louder when heard through water than through a metal. True or false.
A. True
B. False
9
412A man sets his watch by a whistle that is ( 2 k m ) away. How much will his watch
be in error. (speed of sound in air
( mathbf{3 3 0} boldsymbol{m} / boldsymbol{s}) )
A. 3 second fast
B. 3 second slow
( c .6 ) second fast
D. 6 second slow
9
413Which of the following order is correct?
A. Sound ( rightarrow ) ear ( rightarrow ) inner ear ( rightarrow ) vibration of eardrum ( rightarrow )
brain ( rightarrow ) hearing
B. Ear ( rightarrow ) Vibration of eardrum ( rightarrow ) Inner ear ( rightarrow ) hearing ( rightarrow ) brain ( rightarrow ) vibration
C. Sound ( rightarrow ) ear ( rightarrow ) inner ear ( rightarrow ) vibration of eardrum ( rightarrow ) hearing ( rightarrow ) brain
D. Sound ( rightarrow ) ear ( rightarrow ) vibration of eardrum ( rightarrow ) inner ear ( rightarrow ) brain ( rightarrow ) hearing
9
414Describe the principle and use of
SON ( A R ) and ( R A D A R )
9
415Sound waves in air cannot be polarized because :
A. their speed is small
B. they require medium
c. these are longitudinal
D. their speed is temperature dependent
8
416Muscles attached to the vocal cords can
make them
A. tight only
B. loose only
c. both loose and tight as per requirement
D. neither loose nor tight
8
417A road runs midway between two parallel rows of buildings. A motorist moving with a speed of ( 36 mathrm{km} / ) hour sounds the horn. He hears the echo one
second after he has sounded the horn. The distance between the 2 rows of
buildings is (Velocity of sound is 330 ( mathrm{m} / mathrm{s}) )
A. 300 ( m )
B. 150 ( m )
( c cdot 1080 m )
D. 330 m
9
418The term reverberation time is generally understood to be the reverberation time
at which of the following frequencies?
A . ( 1024 mathrm{Hz} )
B . 2048 Hz
c. 512 ( mathrm{H} )
D. 256Hz
9
419If a band is played on the moon the
sound will
9
420State whether true or false.
One canjudge the approaching of a train by laying an ear on the railway track before hearing it.
A. True
B. False
9
421Explain the working and applications of
SONAR.
9
422Outer ear is called
A. Tympanic Membrane
B. Cochlea
C. Pinna
D. Auditory canal
9
423Which of the following is NOT an
application of ultrasound waves?
( A )
в.
( c )
( D )
9
424An ultrasonic wave is sent from a ship towards the bottom of the sea. It is
found that the time interval between the
sending and receiving of wave is 1.6 s. What is the depth of the sea, if the
velocity of sound in sea water is ( 1400 mathrm{m} )
( s^{-1} ? )
A. ( 1120 mathrm{m} )
B. 60 ( m )
( c .1400 mathrm{m} )
D. 112 m
9
425Sound of frequency below ( 20 H z ) is
called
A. audio sounds
B. infrasonic
c. ultrasonic
D. supersonics
9
426The ratio of the absorption of an
auditorium to that of a person is ( 1000 . ) If 500 persons are accommodated in that
auditorium then the ratio of the
reverberation times with and without
audience is:
A ( cdot 1 / 3 )
B. 2/3
( c cdot 3 / 2 )
D. ( 3 / 4 )
9
427A device based on multiple reflection
used as hearing aid.
A. bulb horn
B. ear trumpet
c. megaphone
D. all
9
428The piston in a petrol engine goes up and down 3000 times per minute. For this engine, calculate the period of the piston.
A . ( 0.02 mathrm{s} )
B. 0.04 s
c. ( 0.05 mathrm{s} )
D. 0.08 s
9
429What type of waves are generated by SONAR device fixed to a fishing ship
A)water waves
A. Water waves
c. sound waves
D. Infrared waves
9
430What do you understand by the term Sonar?9
431SONAR is an instrument used for
finding the heights of a mountain.
A. True
B. False
9
432Science fiction films often show battles
between spaceships. Four friends were arguing what would someone in space hear if an enemy spaceship exploded? Rekha said, ‘they would hear a big explosion. Renu saud,’they will not hear anything as there is no medium for sound to
travel, but they can see the explosion. Ramesh said, ‘yes, they will not hear
anything and they will not be able to see the explosion. Raghav said,’the explosion produces sound of frequency above ( 20,000 mathrm{Hz} ) hence we cannot hear it.’
Who is correct?
A. Rekha
B. Renu
C. Ramesh
D. Raghav
9
433SONAR set up consists of :
A. a transmitter
B. a detector
c. channe
D. all of the above
9
434A man stands in between two cliffs and
fires a gun. He hears two successive echoes after 3 sec and 5 sec. What is the distance between two cliffs? (speed of sound ( =330 quad m s^{-1} )
9
435Curved surfaces which are used in big hall to direct the sound waves towards
the people sitting in a hall are known as:
A. megaphone
B. hydrophone
c. bulb horn
D. none of the above
9
436The volume of an auditorium is ( 100 mathrm{m} times )
( 50 m times 15 m . ) The reverberation time in
that auditorium is 2 s when the person
who is giving a speech is at a distance of ( 5 mathrm{m} ) from a wall. The reverberation
time if the same person gives speech at a distance 10m from the wall is
A . ( 1 mathrm{s} )
B. 2
( c cdot 0.5 s )
D. 4 s
9
437The splash of sound was heard ( 5.35 s )
after dropping a stone into a well
122.5m deep. The velocity of sound in
air is:
A. ( 350 mathrm{cm} / mathrm{s} )
в. ( 350 m / s )
c. 392 cm ( / ) s
D. ( 0 mathrm{cm} / mathrm{s} )
9
438What is ‘SONAR’ ? State the principle on which it is based.9
439Which statement about light waves and
sound waves is correct?
A. Both light waves and sound waves show the Doppler effect
B. Light waves can be diffracted but sound waves cannot be diffracted
c. Sound waves are transverse waves and light waves are longitudinal waves
D. Sound waves can travel in a vacuum but light waves control travel in a vacuum.
9
440How does a Sonar work? Explain. Mention its uses9
441An engine moving away from a vertical cliff blows a horn at frequency f. Its speed is ( 0.5 % ) of the speed of sound in air. The frequency of the reflected sound received at the engine is :
A . 0.990
B. 0.995 f
( c .1 .005 f )
D. 1.010
9
442The tympanum of the ear receive the sound in the form of
A. compressions
B. rarefaction
c. both
D. none
9
443What happens when you strike a metal plate with a metal stick?
A. The plate vibrates and produces sound.
B. The plate vibrates and does not produce sound
c. The plate does not vibrate but produces sound.
D. The plate neither vibrates nor produces sound
8
444To hear a distinct echo, the minimum
distance of a reflecting surface should
be
A. ( 7 m )
в. ( 17 m )
( c .27 m )
D. ( 10 m )
9
445Which of the following statements is
wrong?
A. Sound travels in straight line
B. Sound travels as waves
C. Sound is a form of energy
D. Sound travels faster in vacuum than in air
9
446What type of wave is represented by density-distance graph?
A. Transverse wave
B. Longitudinal wave
c. water waves
D. Light waves
9
447If the speed of light in a medium at a given temperature is ( 348 mathrm{m} / mathrm{s} ) at a
pressure of 2 atm. Now the pressure is increased to 5 atm, temperature remaining constant. Now the speed of sound in the same medium will be:
A. Less than ( 348 mathrm{m} / mathrm{s} )
B. Greater than ( 348 mathrm{m} / mathrm{s} )
c. Equal to ( 348 mathrm{m} / mathrm{s} )
D. None of these
9
448If we strike a water-filled bowl with
spoon, then why there is variation in the sound produced due to change in water
level of the bowl?
A. due to change in pitch
B. due to change in amplitude
c. both A and B
D. None of the above
8
449Sonar is a device for
A. Location and ranging of aircrafts
B. Location and ranging of submarines
C. Producing a musical note of high quality
D. Measuring frequency of musical notes
9
450Match the following and choose the
( begin{array}{lllll}A & text { String vibration } & 1 & text { Tabla } \ B & begin{array}{l}text { Membrane } \ text { vibration }end{array} & 2 & begin{array}{l}text { Bicycle } \ text { bell }end{array} \ text { C } & text { Vibration of air } & 3 & text { Sitar } \ text { D } & text { Vibration of plate } & 4 & text { Flute }end{array} )
A . A-1, B-2, C-3, D-4
B. A-2, B-1, C-4, D-3
c. A-3, B-1, C-4, D-2
D. A-4, B-3, C-2, D-1 –
8
451A bicycle wheel spins 25 times in 5 seconds. Calculate frequency of the wheel
A . ( 15 mathrm{Hz} )
B. ( 10 mathrm{Hz} )
c. ( 40 mathrm{Hz} )
D. 5 нz
9
452Sound waves cannot travel through
A. Solids
B. Liquids
c. Gases
D. vacuum
9
453Combination of notes that produced jarring effect on the ear is called
A. discord
B. harmony
c. noise
D. melody
9
454What is necessary for the production and transmission of sound?
A. Medium
B. Acceleration
c. Reciever
D. None of the above
9
455Frequency used in navigating SONAR is
( mathbf{A} cdot 60,000 H z )
в. ( 50,000 H z )
c. ( 20,000 H z )
D. none of these
9
456Reverberation means
A. persistence of sound when intensity of sound from the source is increased
B. persistence of sound when intensity of sound from the source is decreased
C . persistence of sound even when source is turned off
D. persistence of sound when source is moved away
9
457Two tuning forks of frequency 256 and 258 vibrating per second are sounded together, then time interval between
consecutive maxima heard by the observer is.
A . 2 sec
B. 1 sec
c. ( 0.5 mathrm{sec} )
D. 1/4 sec
9
458On stretching a slinky, the regions
where the coils become closer are called
and the regions where coils are
further apart are called
A. rarefaction, compression
B. compression, rarefaction
c. compression, trough
D. rarefaction, trough
9
459In an auditorium the big curtain when falls suddenly then the reverberation
time
A . increases
B. decreases
c. Remains same
D. becomes zero
9
460If you go on increasing the stretching force on a wire in a guitar, its frequency
A. Increases
B. Decreases
c. Remains unchanged
D. None of the above
9
461A mechanical wave travels in a
medium. Which of the following quantities is transferred from one place to another with the wave?
A . Mass
B. Speedd
c. Density
D. Energy
9
462The bulk modulus of a liquid of density
( 8000 k g m^{-3} ) is ( 2 times 10^{9} N m^{-2} . ) The
speed of sound in that liquid is (in
( left.m s^{-1}right) )
A . 200
B. 250
( c cdot 100 )
D. 350
E. 500
9
463Which one of the following will remain unchanged when a sound wave travels in air or in water?
A. Amplitude
B. Frequency
c. wavelength
D. speedd
9
464Mark the correct statement.
A. Time taken by two consecutive compressions or one rarefaction is called the time period of the wave.
B. Sound of a vollin and a flue are different due to the difference in the medium through which they travel.
C. How the brain interpnetes the frequency of an emmitted sound is called pitch.
D. All true
9
465What is the approximate range of audible sound frequencies for a human
with good hearing?
A. From ( 20 H z ) to ( 2000 H z )
B. From ( 20 H z ) to ( 20000 H z )
c. From ( 200 H z ) to ( 20000 H z )
D. From ( 200 H z ) to ( 200000 H z )
9
466When a sound wave travels from water
to air, it
A. bends towards normal
B. bends away from normal
c. may bend in any direction
D. data insufficient
9
467The range of the wavelength of audible sound that travels with a velocity of 330 ( m s^{-1} a t 0^{circ} C ) is ( 16.5 m-16.5 m m )
A. True
B. False
9
468Longitudinal waves cannot travel
through
A. Vacuum
B. Solids
c. Liquids
D. Gases
9
469A rubber string is tied to a nail on the wall. The rubber string is pulled gently to stretch slightly. Which of the following phenomena may occur after the release of the string?
A. Sound is produced
B. Rubber string moves up and down
c. The quality of sound changes with the tension of the string
D. All the above happen
8
470A sonar device fitted in a submarine
receives an echo ( 4 s ) later the signal is transmitted towards another
submarine ( 3060 m ) away. Find the speed of sound in water.
( mathbf{A} cdot 1530 m s^{-1} )
B . ( 1342 mathrm{ms}^{-1} )
c. ( 1600 m s^{-1} )
D. ( 1250 m s^{-1} )
9
471Bells are made of metal and not of wood
because
This question has multiple correct options
A. Metals are elastic than wood
B. The density of the metal is greater than that of wood
C. The sound is not conducted by metals but is radiated
D. Wood dampens vibrations faster
8
472A stone is dropped into a pond from the top of the tower of height, ( h ). If ( nu ) is the speed of sound in air, then the sound of splash will be heard at the top of the tower after a time
A ( cdot sqrt{frac{2 h}{g}}+frac{h}{nu} )
B. ( sqrt{frac{2 h}{g}}-frac{h}{nu} )
c. ( sqrt{frac{2 h}{q}} )
D. ( sqrt{frac{2 h}{g}}+frac{2 h}{nu} )
9
473Fill in the blank.
Shrillness: ( _{text {toudness : }} )
Amplitude
( A ). Pitch
B. Speedd
c. Frequency
D. None of the above
9
474A man fired a bullet against a wall and hears an echo after 2 s. He walks 80 m
towards the wall and fired bullet, such that he hears echo after 1 s. Find the
distance from wall to the second fired
place
A . ( 140 mathrm{m} )
B. 150 ( m )
( c .80 mathrm{m} )
D. 170 ( m )
9
475Sound is produced in a bamboo flute because:
A. air starts vibrating
B. bamboo starts vibrating
c. airhits the bamboo
D. direction of air is changed
8
476Which of the following frequencies of sound elephants produce?
A. ultrasonic
B. infrasonic
( c cdot ) both ( A & B )
D. cant say
9
477An observer ( A ) fires a gun and another observer ( B ) at a distance ( 1650 m ) away
from ( A ) hears its sound. If the speed of
sound is ( 330 m s^{-1}, ) find the time when
( B ) will hear the sound after firing by ( A )
( mathbf{A} cdot 5 s )
в. ( 15 s )
( c .50 s )
D. None of these
9
478A sonar echo takes 8.8 s to return from a
shark. How far away is the shark
( mathbf{A} cdot 348 m )
в. ( 5720 m )
( c .6745 m )
D. 13490 m
9

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