Some Natural Phenomena Questions

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

Some Natural Phenomena Questions

List of some natural phenomena Questions

Question No Questions Class
1 Which of the following is not a aftereffect of earthquake?
A. Destruction of livelihood
B. Death and injuries
c. water waves and tsunamis
D. Rainfall
8
2 Earthquake can cause
A. Tsunami
B. Floods
c. Landslide
D. All of the above
8
3 State whether the given statement is
True or False :
Tremors on the Earth can also be
caused by the eruption of a volcano.
A. True
B. False
8
4 When the convex lens acts as a
magnifying glass, the object is between the ( ldots ldots ldots . . ) and the optical centre of lens.
10
5 Fill in the blanks:
During the development of a thunder-
storm, the air currents move
while the water droplets
move
A. downward, upward
c. downward, downward
D. upward, upward
8
6 you are aware of the natural reasons for
the occurrence of earthquakes. mention the man-made reasons
( (s) ) of
earthquake
8
7 S’ waves are
A. Longitudinal
B. Electromagnetic
C. Ultrasonic
D. Transverse
8
8 The sparks caused due to friction between two machine parts are:
A. similar to lighting
B. not similar to lightning
c. lightning on a very small scale
D. none of the above
8
9 A transparent cube of side ( boldsymbol{d}, ) made ot a
material of refractive index ( mu_{2}, ) is
immersed in a liquid of refractive index
( mu_{1}left(mu_{1}<mu_{2}right) . ) A ray is incident on the
face ( A B ) at an angle ( theta ) (shown in the
figure). Total internal reflection takes
place at point ( boldsymbol{E} ) on the face ( boldsymbol{B} boldsymbol{C} )
The ( theta ) must satisfy:
( mathbf{A} cdot theta<sin ^{-1} frac{mu_{1}}{mu_{2}} )
B ( cdot quad thetasin ^{-1} frac{mu_{1}}{mu_{2}} )
( ^{mathrm{D}} theta>sin ^{-1} sqrt{frac{mu_{2}^{2}}{mu_{1}^{2}}-1} )
10
10 A thunderstorm is generally accompanied by:
A . lightning
B. earthquake
( c . ) fire
D. mild breeze
8
11 What is the approximate lightning frequency?
A. 1.4 billion flashes per year
B. 1.4 billion flashes per month
c. 1.5 billion flashes per year
D. 1.6 billion flashes per yea
8
12 A mark placed on the surface of a sphere is viewed through glass from a position directly opposite. If the diameter of the sphere is ( 10 mathrm{cm} ) and refractive index of glass is ( 1.5 . ) The position of the image will be :
( A .-20 mathrm{cm} )
B. 30 cm
c. ( 40 mathrm{cm} )
D. -10 cm
10
13 Accumulation of charges causes in the clouds.
A . rain
B. earthquake
c. lightning
D. storm
8
14 Electric spark is the electrical discharge when a electric
field creates an ionised channel. Fill in
the blank.
A. sufficiently strong
B. moderate
c. weak
D. very weak
8
15 Consider the situation shown in figure.
The elevator is going up with an acceleration of ( 2.00 m / s^{2} ) and the focal
ength of the mirror is ( 12.0 mathrm{cm} . ) All the
surfaces are smooth and pulley is light.
The mass-pulley system is released from rest (with respect to the elevator)
at ( t=0 ) when the distance of ( B ) from
the mirror is ( 42.0 mathrm{cm} ). Find the distance
between the image of the block ( B ) and
the mirror at ( t=0.200 s . ) Take ( g= )
( 10 m / s^{2} )
10
16 Light of a single colour is passed through a liquid having a piece of glass suspended in it. On changing the temperature of liquid, at a particular temperature the glass piece is not seen. The glass piece is not seen when the refractive index of liquid becomes
the refractive index of the
glass.
A. greater than
B. less than
c. equal to
D. cant say
10
17 Storms, cyclones, earthquake, lightning etc. are ( ldots ldots . . . . . . . ) natural phenomena:
A. constructive
B. destructive
c. simple
D. complex
8
18 Match the following and choose the
correct answer.
begin{tabular}{lll|l}
& table A & & table B \
a. & Earthquake & 1. & Prevent leakage \
b. & Lightning & 2. & Faultzone \
c. & Insulation & 3. & Detection of charges \
d. & Electroscope & 4. & Earthing
end{tabular}
A. ( a-2, b-4, c-1, d-3 )
B. ( a-3, b-4, c-2, d-1 )
c. ( a-4, b-3, c-2, d-1 )
D. ( a-1, b-2, c-3, d-4 )
8
19 What is absolute refractive index?
A. Refractive index with respect to air
B. Refractive index with respect to vacuum
C. Refractive index with respect to water
D. Refractive index with respect to glass
10
20 t is desired to orbit an erect image of an object, using concave mirror of a
focal length of ( 12 mathrm{cm} )
1. What should be the range of distance
( p ) an object placed in front of the mirror?
2. Will the image be smaller or large then the object? Draw the ray diagram to show the formation of an image in this case?
3. Will the image be smaller or large then the object? Draw the ray diagram to show the formation of the image in this case?
4. Where will the image of the object be, fit is placed ( 24 c m ) in front of the
mirror?
Draw ray diagram for this situation also justify your answer
10
21 In the process of earthing, how does charges get discharged to Earth?
A. Through some conductor
B. Directly to the Earth
c. Through transformer
D. None of the above
8
22 Light wave of frequency ( 4 times 10^{14} mathrm{Hz} )
passes through a medium. The wave
length in the medium is ( lambda=5 times 10^{-7} )
m. The refractive index of the medium
is:
( A cdot 2 / 3 )
B. ( 4 / 3 )
( c cdot 3 / 2 )
D. 1.414
10
23 A convex lens forms a e real image three times larger than the object on a screen Object and screen are moved until the image becomes twice the size of the object. If the shift of the object is ( 6 mathrm{cm} ) The shift of screen is
A . 36 ( mathrm{cm} )
B. 72 cm
c. ( 18 mathrm{cm} )
D. ( 9 mathrm{cm} )
10
24 Identify the correct statement about
light rays:
A. light propagate along a straight line
B. two light rays donot disturb each other upon intersection
C . object and its image are inter-changeable
D. none of these
10
25 When, on large scale, negative and positive charges meet in clouds, we experience:
A. streak of bright light and sound
B. thunderstorm
c. lighting
D. all of the above
8
26 The natural phenomenon which we are not yet able to predict accurately is:
A. earthquake
B. flood
c. volcanic erruption
D. thunderstorm
8
27 State whether true or false:
A concave lens is used as a magnifying glass
A. True
B. False
10
28 The plates or the fragments of the Earth’s crust is also known as:
A. crust plates
B. surface plates
c. tectonic plates
D. none of the above
8
29 Derive Newton’s formula for thin lens. 10
30 If a lens diverges a parallel beam of light, the lens is –
A. convex
B. Concave
c. cylindrical
D. Parabolic
10
31 Which is an intensive property?
A. Volume
B. Mass
C. Refractive index
D. weight
10
32 An object ( 4.0 mathrm{cm} ) in size, is placed 25.0 ( mathrm{cm} ) in front of a concave mirror of focal
length ( 15.0 mathrm{cm} )
(i) At what distance from the mirror
should a screen be placed in order to obtain a sharp image?
(ii) Find the size of the image.
(iii) Draw a ray diagram to show the formation of image in this case.
10
33 It is safer to use mobile and cordless
phone during lightning because?
A. They are wireless
B. Less chances of getting in contact with lightning
c. Both a ( & mathrm{b} )
D. None of the above
8
34 is nature’s most powerful display of static electricity.
A. Current electricity
B. Lightning
c. conduction
D. Induction
8
35 What kind of lens would form an
inverted and magnified image?
10
36 Which nutrient is produced when large amount of energy breaks the atom bonds of nitrogen?
A. Protein
B. Mineral
c. Iron
D. Calcium
8
37 Telescope uses and
microscope uses
A. Two convex lenses, Two Concave lenses
B. One convex lens, One Concave lens
C. Two convex lens, one concave lens
D. Two convex lens, two convex lens
10
38 The optical path of a monochromatic light is same if it goes through ( 4.0 mathrm{cm} ) of glass of ( 4.5 mathrm{cm} ) of water. If the
refractive index of glass is 1.53 , the refractive index of the water is:
A . 1.30
B. 1.36
c. 1.42
D. 1.46
10
39 State whether given statement is True or False.

Lightning rods are placed on houses to reduce risk of lightning damage to low.
A. True
B. False

8
40 Two objects ( A ) and ( B ) when placed in front of a concave mirror of focal length
( 7.5 mathrm{cm}, ) give images of equal size. If ( mathrm{A} ) is three times the size of ( B ) and is placed ( 30 mathrm{cm} ) from the mirror, what is the distance of B from the mirror?
( mathbf{A} cdot 10 mathrm{cm} )
в. ( 12.5 mathrm{cm} )
( mathbf{c} cdot 15 c m )
D. ( 17.5 mathrm{cm} )
10
41 A mobile phone lies along the principal axis of a concave mirror. Show with the
help of suitable diagram, the formation of its image. Explain why magnification is not a uniform?
10
42 A rod of length ( 10 mathrm{cm} ) lies along the principal axis of concave mirror of focal length ( 10 mathrm{cm} ) in such a way thatits end closer to the pole is ( 20 mathrm{cm} ) away from the mirror. The length of the image is
then –
( mathbf{A} cdot 15 mathrm{cm} )
B. 2.5 ( mathrm{cm} )
( c cdot 5 mathrm{cm} )
D. ( 10 mathrm{cm} )
10
43 The device that is used to protect
buildings from the effects of lightning is:
A. transformer
B. transducer
c. electrode
D. lightning conductor
8
44 A virtual image larger than the object can be produced by a :
A. concave lens
B. concave mirror
c. convex mirror
D. plane mirror
10
45 What is lightning conductor? How does it save high rise buildings from
lightning damage?
8
46 A concave lens is used in:
A. a simple camera
B. spectacles for the correction of short sightedness
C . a magnifying glass
D. vehicles to see objects on rear side
10
47 State whether given statement is True or False.

Charges are incapable of passing from clouds to lightning rod.
A. True
B. False

8
48 A telescope makes use of
A. convex lenses
B. concave lenses
C. either convex or concave lenses
D. neither convex nor concave lenses
10
49 Prove that for spherical mirrors the products of the distance of the object and the image to the principles focus is
always equal to the square of the principles focal length.
10
50 When an object is kept within the focus of a concave mirror, an enlarged image is formed behind the mirror. The nature
of the image is:
A . Real
B. Inverted
c. Virtual and inverted
D. Virtual and erect
10
51 A glass slab has concave surface of
radius of curvature ( 2.0 mathrm{cm} . ) The glass
has refractive index of ( 1.5 . ) If a point object is placed on axis in air at a
distance of ( 18 mathrm{cm} ) from concave face,
find the position and nature of the image.
10
52 A ray of light is incident on a
rectangular plate at an angle of
incidence ( 60^{circ} . ) The light ray suffers a
deviation which is ( 25 % ) of the angle of incidence. The refractive index of the
glass will be
A ( cdot sqrt{3} )
B. ( sqrt{2} )
c. ( sqrt{frac{3}{2}} )
D. 1.5
10
53 A point on the principal axis of a lens, to which light rays parallel to the principal axis converge after passing through the lens, is
A. Centre of curvature
B. Origin
c. Focus
D. optical centre
10
54 State whether given statement is True/False?

Lightning conductor is made up of
copper.
A. True
B. False

8
55 A person is looking at the image of his face in a mirror by holding it close to his face. The image formed is virtual. When he moves the mirror away from his face, the image is inverted. What type of mirror is he using?
A. Plane mirror
B. Concave mirror
c. convex mirror
D. Combination of mirror and lenses
10
56 The lightening conductor is connected to interface with ground or “earth” through
( A cdot ) a cathode
B. an anode
c. an electrode
D. a semiconductor
8
57 What should be the length of the metal rod used as lightning conductor?
A. shorter than the walls of the building
B. Same length or equals.
c. Taller than the walls of the building
D. Nothing specific, can be of any length.
8
58 The earth shakes when
occurs.
A. Tsunami
B. Flood
c. Earthquake
D. Drought
8
59 Fill in the blanks:
Principal axis is also called of the lens.
A. Optical axis
B. x-axis
c. y-axis
D. axis
10
60 Two concave lenses ( L_{1} ) and ( L_{2} ) are kept
in contact with each other. If the shape between the two lenses are filled with a
material of smaller refractive index the
magnitude of the focal length of the combination
A. becomes undefined
B. remains unchanged
c. Increase
D. Decrease
10
61 Oppositely charged clouds, coming closer to each other, cause:
A. induction
B. conduction
c. lightning
D. none of the above
8
62 A microscope makes use of
A. convex lenses
B. concave lenses
c. both convex and concave lenses
D. no lenses at all
10
63 The refractive index of prism is 2. The prism can have a maximum refracting angles of
A ( .90^{circ} )
B. ( 60^{circ} )
( c cdot 45^{circ} )
D. ( 30^{circ} )
10
64 Which of the following descriptions apply
to a lightning conductor?
A. It is usually fixed at the top of tall buildings
B. It has several metal stripes connected to a copper strip
C. One end of the conductor is buried deep under the ground
D. All of the above
8
65 Suppose you are in a car and it is raining heavily with thunderstorms. Then what is the best way to protect yourself from a possible thunder-strike?
A. To remain in the car
B. To get out of the car and take cover under the car
c. To run to a nearby tree
D. To get out and stand under an electric pole
8
66 Lightning is caused due to discharge of
oppositely charged clouds. Give reason.
8
67 Fill in the blank
is pattern of electrical
charges in Earth’s atmosphere.
A. Electricity
B. Space electricity
c. Ground electricity
D. Atmospheric electricity
8
68 If you are travelling by car during thunderstorm which place is safe?
A. Under a tree
B. Near street light
C. Elevated places
D. None of the above
8
69 Read the following conversation. Teacher: “If you want to collect virtual
image, which mirror do you select?” Bharathi: “convex mirror”
Sowmya: “concave mirror” Firoz : “plane mirror”
What do you think? Who is correct?
Explain
10
70 A lightning conductor installed in a
building
A. does not allow the lightning to fall on the building
B. repels the lightning
C. forces the lightning to fall in an area where there are no buildings
D. conducts electric charge to the ground when lightning strikes the building
8
71 Earthquakes can be predicted in advance
A . True
B. False
c. Ambiguous
D. Data insufficient
8
72 The movement of Earth’s plates causes
A. Lightening
B. Cyclons
c. Earthquake
D. Thunderstorms
8
73 The streaks of bright light seen during lightning is essentially the path followed by:
A. UV rays from Sun
B. cosmic rays
c. accumulated electric charges
D. none of the above
8
74 Define the principal focus of a convex lens and that of a concave lens. 10
75 Fill in the blank:
charges collect or
accumulates near the lower edges of
clouds.
A. Positive
B. Neutral
c. Negative
D. None of the above
8
76 Choose the correct statement.
A. ‘P’ waves are slower than ‘S’ waves.
B. Both’P’ and ‘S’ waves have same speed.
C. ‘S’ waves are slower than’P’ waves.
D. None of the above.
8
77 State whether the given statement is
True or False :

Lightning conductor always develops the opposite charges as is the charge in
the clouds.
A. True
B. False

8
78 The change in the shape of the lens
while seeing distant and nearby objects
10
79 Point at which all rays converge is termed as
A. Converging point
B. Focal point
c. Focal center
D. Converging center
10
80 What is the refractive index of a
medium?
A. The ratio of the speed of light in air to the speed of light in the medium
B. The ratio of the speed of light in the medium to the speed of light in air
C. The ratio of the speed of light in the medium to the speed of light in vaccum
D. The ratio of the speed of light in vacuum to the speed of light in the medium
10
81 Instrument used to measure
earthquake is known as:
A. Typanic graph
B. Seismograph
c. Quake graph
D. Quake meter
8
82 Atmospheric electricity is generated
due to
A. the accumulation of static charges
B. the accumulation of moving charges
C. the destruction of static charges
D. destruction of moving charges
8
83 a concave mirror is shown by ( boldsymbol{P} boldsymbol{Q} ) while
directions in which the ray would travel
after reflection is shown by four rays
marked 1,2,3 and 4

Which of the four rays correctly shows
the direction of reflected ray?
( A cdot 4 )
B. 3
( c cdot 2 )
( D )

10
84 Which of the following statement is
correct?
A. The earth’s surface is negatively charged
B. The earth’s surface is positively charged
C. The earth’s surface is neutral
D. None of the above
8
85 Lightning occurs because of :
A . rain
B. electric discharge
( c . ) wind
D. shaking of earth
8
86 State whether the given statement is True or False :
To process nitrogen, lightning and other processes help in life existence.
A. True
B. False
8
87 A lightning conductor:
A . conducts light
B. stops lightning
C. protect building from the damaging effects of lightning
D. none of these
8
88 Static charges in the atmosphere is generated by
A. induction from the earth’s surface
B. conduction between clouds
c. friction of the air upon itself
D. No reason
8
89 In the given figure, diameter of
lens equals
( A cdot F O )
B. 2FO
( c cdot 3 F O )
D. ( 4 mathrm{FO} )
10
90 The angle which subtends the periphery of the spherical mirror at the centre of curvature is called:
A. angular aperture
B. glancing angle
c. critical angle
D. none of these
10
91 The rsultant power of combination 10
92 What kind of lens would form an
inverted diminished image?
10
93 Fill in the blank:
charges collect near the upper edges of the clouds.
A. Negative
B. Positive
c. Neutral
D. No
8
94 The ratio of the size of the image to the size of the object is known as
A. focal plane
B. transformation ratio
c. efficiency
D. magnification
10
95 Write ( T ) against true and ( F ) against false in the following statements:
(a) Like charges attract each other (T/F)
(b) A charged glass rod attract a charged plastic straw (T/F)
(c) Lightning conductor cannot protect a building from lightning (T/F)
(d) Earthquakes can be predicted in advance (T/F)
8
96 When we can observe sparks on an
electric post?
A. When there is huge rain
B. When there is thunderstorm
C. When wind blows and shakes the wire
D. All of the above
8
97 What is an earthquake? List the precautions that need, to be taken during an earthquake if one is staying indoors or outdoors. 8
98 From below what are the properties of
concave mirrors?
A. Converging mirrors and form real and inverted image in front of the mirror
B. Diverging mirrors and form virtual and upright image behind the mirror.
C. Converging mirrors and form virtual and inverted image in front of the mirror.
D. Diverging mirrors and form real and inverted image in front of the mirror.
10
99 Fill in the blank:
A sudden shaking or trembling of the Earth, caused by a disturbance deep inside the Earth’s crust, is known as
A. tsunami
B. flood
c. earthquake
D. landslides
8
100 An earthquake is caused by
A. shaking of the earth
B. strain building up in the tectonic plates
C . plates slipping along the fault lines
D. all of the above
8
101 Which of the following correctly presents the sequence of operations of isolator circuit breaker and earthing switch while closing a circuit :
A. Ensure circuit breaker is closed – close isolator – open earthing switch
B. Ensure circuit breaker is open – close isolator – open earthing switch if any close circuit breaker
C. Ensure circuit breaker is open – open isolator – open earthing switch if any close circuit breaker
D. None of the above
8
102 Fill in the blank:
of charges on surfaces of clouds leads to lightning.
A. Accumulation
B. Leakage
c. conduction
D. Induction
8
103 What is a lighting conductor? How does
it protect?
8
104 Buildings are more susceptible to a lightning strike because
A. they are higher than their surroundings.
B. roofs of buildings are wet in rainy season and hence become good conductors of electricity.
c. the top of the building is wet and acquires an opposite charge to a cloud passing over the top by induction
D. All of the above
8
105 A student obtains a blurred image of an
object on a screen by using a concave
mirror. In order to obtain a sharp image
on the screen, he will have to shift the
mirror:
A. towards screen.
B. away from the screen.
C. either towards or away from the screen depending upon the position of the object.
D. to a position very far away from the screen.
10
106 In one year lightning produces how much amount of usable nitrogen fertilizer?
A . 250000 tons
B. 25000 tons
c. 250 tons
D. 25 tons
8
107 A ray incident at an angle of incidence
( 60^{0} ) enters a glass sphere of refra
A . ( 30^{circ} )
B . ( 45^{circ} )
( c cdot 65^{circ} )
D. ( 90^{circ} )
10
108 Lightning conductor is made up of conducting materials.
A. True
B. False
8
109 Seismic waves that vibrate
perpendicular to the direction of their
path.
A. Spread on the surface of the earth
B. Travel through the solid as well as other parts of the earth
C. Travel through the solid parts of the earth only
D. None of the above
8
110 The ray diagram shown below is
introduced to show how a concave
mirror forms an image of an object
a) Identify the mistake and draw the
correct ray diagram
b) Write the justifications for your
corrections.
10
111 Which of the following is not a type of lightning?
A. Intracloud (IC)
B. Cloud to Cloud (CC)
c. Cloud to Ground (CG)
D. Ground to Cloud (GC)
8
112 Can lighting occur thunder? Justify
your answer.
8
113 The Radius of curvature of two surfaces
of a convex lens are ( 10 mathrm{cm} ) and ( 20 mathrm{cm} )
respectively. The refrective index of glass is 1.5 then determine focal length of the lens.
10
114 Fill in the blanks:
The most tremor-threatened areas in
India are Kashmir, and
A. Western, Eastern Himalayas
B. Northern, Western Himalayas
C. Eastern, Central Himalayas
D. Western, Central Himalayas
8
115 A convex mirror with a radius of
curvature of ( 3 m ) is a used as rear view
mirror for a vehicle. If a bus is located at
( 5 m ) from this mirror, find the position, nature and size of the image.
10
116 Lightning rod can be most effective if it draws charge from lowest cloud by method of contact. This statement is
True/ False?
A. True
B. False
8
117 A ray of light strikes a transparent rectangular slab of refractive index ( sqrt{2} ) at an angle of incidence of ( 45^{circ} . ) The angle between the reflected and refracted rays is :
A ( .75^{circ} )
В. ( 90^{circ} )
( c cdot 105 )
D. ( 120^{circ} )
10
118 A camera is an optical instrument which makes use of a :
A. convex lens
B. concave lens
c. cylindrical lens
D. planar lens
10
119 State whether the given statement is
True or False.

A concave lens is always tapering at edges and thicker in the middle.

10
120 What is the main function of lightning conductor?
A. To capture lightning stroke and conduct discharge current safely to the ground
B. To capture lightning stroke and conduct discharge current safely to the cloud
C. To capture lightning stroke and conduct discharge current safely to the building
D. None
8
121 A fish looking up through the water sees the outside world in a circular horizon. If
the refractive index of water is ( 4 / 3 ) and
the fish is ( 12 m ) below the surface, the
radius of the circle in ( mathrm{cm} ) is
A. ( 36 sqrt{7} )
в. ( frac{36}{sqrt{7}} )
c. ( 36 sqrt{5} )
D. ( 4 sqrt{5} )
10
122 Why earthing is important?
A. To protect us from electrical shocks.
B. Transfers charge from a charged body to the Earth.
C. Both A and B.
D. Neither A nor B.
8
123 Light from the sun strikes the concave
mirror pictured below. The image of the
sun is formed at the point indicated.
When we place an object closer to the
mirror than this point, what are the
characteristic of the image formed
(Size is compared to object)?
A. Larger, real, inverted
B. Smaller, real, inverted
c. Smaller, virtual, upright
D. Larger, virtual, upright
E. No image is formed
10
124 A lightning conductor consists of
A. several sharp metal spiked connected to a thick copper strip.
B. a metal plate buried deep inside the ground connected to the ground end of copper strip.
C. a conductor fixed on top of the building.
D. all of the above
8
125 Virtual image cannot be caught on a
screen
A . True
B. False
10
126 The weather department has predicted that a thunderstorm is likely to occur on
a certain day. Suppose you have to go
out on that day. Would you carry an umbrella? Explain.
8
127 Why it is not recommended to touch
water metal-pipe lines, electric wires during thunderstorm?
A. They are good conductors thus may carry charges.
B. They are insulators and never carry charges.
c. They may store charges
D. This is a myth.
8
128 What would you use to obtain a real and inverted image for any position of an object ?
A. a concave mirror or a concave lens
B. a convex mirror or a convex lens
c. a concave mirror or a convex lens
D. a convex mirror or a concave lens
10
129 When light is going from vacuum to another medium, then the value of refractive index is called:
A. Relative refractive index
B. Absolute refractive index
c. critical angle
D. None
10
130 Object is placed between infinity and a device. Image formed is diminished and between pole and focus, behind it. If the image is virtual and erect, identify the device.
A. Convex mirror
B. Concave mirror
c. Spherical mirror
D. Plane mirror
10
131 An object is lying at a distance of ( 90 mathrm{cm} ) from a concave mirror of focal length
( 30 mathrm{cm} . ) The position and nature of image formed by it will be:
A. ( 45 mathrm{cm} ), of the size to object
B. ( 95 mathrm{cm} ), smaller than object
c. ( 35 mathrm{cm} ), bigger than object
D. ( -45 mathrm{cm}, ) smaller than object
10
132 A real image, equal in size to the object, is obtained when the object is placed at the centre of curvature in front of a:
A. Concave mirror
B. Plane mirror
c. Convex mirror
D. None of these
10
133 The term used to describe a fracture
along the earth’s crust is
A. aftershock
B. fault
c. focus
D. tremor
8
134 Fill in the blanks:
The distance between pole and focus is
10
135 Which of the following is/are true regarding Earthquake?
A. It refers to shaking of the Earth.
B. It occurs due to release of energy
c. It generates waves that travel in all direction.
D. All of the above.
8
136 The ratio of the speed of light in a vacuum to the speed of light in a particular material is called what?
A. the coefficient of diffraction of the material.
B. the index of refraction of the material
c. the coefficient of refraction to the material
D. the index of diffraction of the material.
E. the modulus of diffraction of the material.
10
137 How can we be safe when there is
occurrence of lightning?
A. Taking shelter under building or house
B. When travelling through car or bus, making sure windows and doors are shutt
C. If in forest, taking shelter under short trees
D. All of the above
8
138 Fill in the blank.
Static electricity produced by charged particles in the atmosphere is known
as
A. Atmospheric electricity
B. Atmospheric charge
c. cloud electricity
D. Wind electricity
8
139 The refractive index of water with
respect to air is ( _{a} mu_{w} ) and of glass with respect to air is ( _{a} mu_{mathrm{g} cdot} ) So, ( frac{a mu_{g}}{a mu_{w}} ) should
express:
A. refractive index of glass with respect to water
B. refractive index of water with respect to glass
C. refractive index of air
D. none of these
10
140 Describe the mechanism of occurrence
of an earthquake with the help pf pictorial representation.
8
141 When a light ray is directed parallel to
principal axis of a concave mirror
A. real image is formed
B. a diminished image is formed
c. inverted image is formed
D. All the above
10
142 Assertion
Virtual object can’t be seen by human
eye
Reason
Virtual object is formed by converging
rays.
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
10
143 A real image is formed where two or
more :
This question has multiple correct options
A. reflected rays meet
B. refracted rays meet
C . reflected rays appear to meet
D. refracted rays appear to meet
10
144 Franklin showed that
the spark from our clothes during winters are the same phenomena. Fill in the blanks.
A. thunder-storm
B. earthquake
c. lightning
D. rain
8
145 Convex lens
A. Shrinks the image
B. Magnifies the image
C. sharpens the image
D. Increase the contrast of the image
10
146 What kind of lens would form an erect
and diminished image?
10
147 Focal point of a lens is a point where
A . light spreads
B. light rays meet
c. light rays spread to meet
D. lens can magnify the most
10
148 The fact that lightning and spark are essentially the same phenomena, was discovered in:
A . 1882
B. 1752
c. 177
D. 1802
8
149 State whether true or false:
A concave mirror can produce both real and virtual images.
A. True
B. False
10
150 A simple microscope is used by watchmakers. Given reason. 10
151 A container is filled with water ( (mu= )
1.33) upto a height of ( 33.25 mathrm{cm} . ) A
concave mirror is placed ( 15 mathrm{cm} ) above
the water level and the image of an object placed at the bottom is formed ( 25 mathrm{cm} ) below the water level. The focal
length of the mirror is
( mathbf{A} cdot 10 )
B. 15
( c .20 )
D. 25
10
152 Where is the lower end of a lightning conductor fixed in the building?
( A cdot ) at the top
B. at a window
c. at the base
D. in the ground
8
153 Lightning is nothing but
A . electric discharge
B. electricity
c. electro – magnetic discharge
D. magnetic effect
8
154 Fill in the blank:
The uppermost layer of the Earth is called
A. mantle
B. outer core
c. crust
D. none of the above
8
155 The focal length is the distance from the optical center of the lens and its principal
A. focus
B. axis
c. center of curvature
D. Iens
10
156 Mention factors which determine the
extent of damage due to an earthquake?
8
157 The S.I. symbol for refractive index is ( r )
A. True
B. False
10
158 All living things depend on which chemical element?
A. Oxygen
B. Nitrogen
c. Hydrogen
D. Phosphorous
8
159 Lightning conductors are used to save the building from earthquakes.
A. True
B. False
8
160 State whether the given statement is True or False:

Whenever there is a lightning, there is an earthquake.
A. True
B. False

8
161 is engineered to protect an
elevated structure in the event of
lightning strike.
A. A lightning conductor
B. Copper wire
c. A lightening shield
D. All of the above
8
162 What are seismic waves caused by?
A. Volcanoes
B. Traffic
c. Earthquakes
D. Heavy rain
8
163 The Earth’s crust is fragmented and each fragment is known as:
A. a spott
B. a plate
c. a valley
D. none of the above
8
164 What is meant by lightning?
A. It is sudden electrostatic discharge during an electrical storm between electrically charged regions of cloud.
B. It is sudden electrostatic discharge during an electrical storm between non-electrically charged regions of cloud
C. It is unsudden electrostatic discharge during an electrical storm between electrically charged regions of cloud.
D. None of the above
8
165 When you are in forest during lightning which is safe place?
A. Open field
B. Under tall trees
c. Under short trees
D. None of the above
8
166 The intensity of an earthquake is
measure on the ( -? )
A. Righter scale
B. Richter scale
c. Seismic scale
D. None of the above
8
167 Why should the height of lightning conductor is more than that of the walls
of the building?
A . Lightning get attracted towards the tallest target
B. Lightning get repelled
c. Lightning get attracted by the walls of building
D. None of the above
8
168 What is earthing?
A. Passage of large electric current resulting from a lightning into the earth
B. Burying electric charge into the earth
C. Preventing electric charge from entering the earth
D. None of the above
8
169 The boundaries of the plates, called weak zones, are also known as:
A. danger zones
B. seismic zones
c. colliding zones
D. none of the above
8
170 Which of the following country in the world is most prone to earthquake?
A. India
B. America
c. china
D. Japan
8
171 Draw a ray diagram to show the formation of image by a convex lens when an object is placed in front of the lens between its optical centre and principal focus. 10
172 When a beam of light from an object
appears to meet at a point after reflection from a mirror then the image formed is known as:
A. Real image
B. Virtual image
c. Incident image
D. All
10
173 The amplitude of vibrations measured on the Richter’s scale increase by steps of about
A . 10
B. 20
( c . ) 30
D. 40
8
174 The intensity of atmospheric electric
field is :
A. same in winter as in summer
B. lesser in winter than in summer
c. greater in winter than in summer
D. none of the above
8
175 The distance between the focus and the
pole of the mirror is called:
A. Focal length
B. Radius of curvature
c. Principal axis
D. Diameter of curvature
10
176 The angle of reflection is
( A cdot 25 )
B ( .12 .5^{circ} )
( c cdot 50^{circ} )
D. None of these
10
177 The safest place during a thunderstorm is:
A. Under a tree
B. Near electricity poles
c. Inside a car
D. Lying on the ground
8
178 Light from a point source in air falls on a spherical glass surface whose radius of curvature and refractive index are 20
( mathrm{cm} ) and 1.5 respectively. If the distance of light source from the glass surface is ( 100 mathrm{cm}, ) then at which position image will be formed?
( A cdot 25 mathrm{cm} )
B. 50 ( mathrm{cm} )
( c .100 mathrm{cm} )
D. 200 cm
10
179 Earthquake is also known as:
A. nektons
B. blusters
c. temblors
D. flickers
8
180 Name the scale on which the
destructive energy of an earthquake is measured.
A. Temperature scale
B. Vector scale
c. Richter scale
D. Energy scale
8
181 Show an experiment which proves light always travels in a straight line. 8
182 The lightning conductor used in building, protects the building by :
A. dissipating the electric charge away from the building
B. conducting the lightning safely to the ground
c. absorbing the electric charge
D. None of these
8
183 State whether the given statement is True or False :

Earthquakes occur all the time all over
the world.
A. True
B. False

8
184 Fill in the blank:
In ( 1752, ) scientist Benjamin Franklin showed that lightning and spark from our clothes are ( _{-}-_{-}- ) – phenomena
A. same
B. different
c. simultaneous
D. none of these
8
185 was the first to discover
that lightning is electric discharge.
A. Thomas Alva Edison
B. Nicolas Tesla
c. Benjamin Franklin
D. Isaac Newton
8
186 When a beam of white light parallel to the principal axis is refracted through a convex lens, then the rays converge to the principal axis. If a screen is placed at a sufficient distance from the focus-
point perpendicular to the principal axis then the image on the screen will be
A. A sharp white point
B. A sharp violet point or red point
c. A circular spot whose edges are violet and central portion red
D. A circular spot whose edges are red and central portion violet
10
187 Is lightning static electricity?
A. Yes
B. No
c. sometimes
D. None of the above
8
188 What is convex mirror?
A. curved or bowed outward like outside of a bowl or
sphere
B. curved like inner surface of a bowl or sphere
c. curved inward
D. None
10
189 Mark the incorrect statement:
A. The principal focus of a spherical mirror lies midway between the pole and centre of curvature
B. For spherical mirrors of small aperture, ( R=frac{f}{2} )
C. Centre of curvature lies outside its reflecting surface
D. All
10
190 A point within the lens, where a line drawn through the diameter of lens meets principal axis is known as
A. Focal length
B. Optic Center
c. Aperture
D. center of curvature
10
191 The intensity of the
atmospheric electric field is, normally,
A. greater in the middle of the day than at morning
B. smaller in the middle of the day than at morning
C. same in the middle of the day as at morning
D. zero in the middle of the day and at morning
8
192 When did a major Tsunami occur in the
Indian ocean?
A ( cdot ) on ( 26^{t h} ) December, 2004
B. On ( 26^{text {th }} ) July, 2004 .
c. on ( 26^{text {th }} ) December, 2001
D. on ( 26^{t h} ) July, 2001
8
193 Find the position of the object which
when raised in front of convex mirror of
focal length ( 20 mathrm{cm} ) produces virtual image which is half size of the object.
10
194 The spark seen inside a switch is:
A. electrical discharge
B. due to heating effect of current
C . an indicator glowing
D. a sudden fire
8
195 How much percentage of atmosphere is made of nitrogen?
A. 78percent
B. 90percent
c. 88 percent
D. 82 percent
8
196 A concave lens can form
A. An erect magnified image
B. An erect diminished image
C. An inverted magnified image
D. An inverted diminished image
10
197 Refractive index of a transparent medium, so that it is invisible in
vacuum is
( A )
B. ( 1.33 )
D. 1.33
10
198 Assertion
When super charged particles enter the earth’s atmosphere from the solar wind, they spiral around the magnetic field lines of the earth.
Reason
They tend to be channelled toward the poles by magnetic forces.
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
199 The point where the waves originate is called the ( _{-}–_{-}- ) of the earthquake
A. centre
B. epicenter
c. focus
D. origin
8
200 State whether true or false:
Lightning conductors are used to save the building from earthquakes.
A. True
B. False
8
201 Which of the following colors has maximum refractive index?
A . Red
B. Violet
c. Green
D. Yellow
10
202 Which of the following is permissible during a thunderstorm?
A. Using a telephone having cord
B. Using a mobile phone
c. Taking a bath under running water
D. standing under a tree
8
203 ( mu_{1}, mu_{2} ) are the refractive indices of two
media A and B. If ( mu_{1}>mu_{2}, ) when two
light rays travel from air to medium ( mathbf{A} ) and air to medium B with the same
angle. of incidence then the angle of
refractions are ( r_{1} ) and ( r_{1} ) respectively.
What is the relation between ( r_{1} ) and ( r_{2} ? )
A. ( r_{1}=r_{2} )
B . ( r_{1}r_{2} )
D. ( r_{1} geq r_{2} )
10
204 Each of these diagrams is supposed to show two different rays being reflected from the same point on the same mirror Which option is correct:-
A. Only i
B. only ii
c. only iii
D. All
10
205 How does lightning help the atmosphere?
A. Increases the temperature
B. Brings rain
c. Increases the ozone layer
D. Unsure
8
206 Clouds get electrically charged when:
A. The UV rays of sun falls on them
B. Air molecules rub against water molecules
C. Cold currents of air rub against hot currents of air
D. Both B and C
8
207 A ray of light, after refraction through a
convex lens emerges parallel to the
principal axis. The incident ray when produced appear to come from a point on principal axis. Name the point :
A. first focus
B. first centre
c. last focus
D. last centre
10
208 Two plane mirrors are set at right angles and a flower is placed in any position in between the mirrors. The number of images of the flower which will be seen is
A. one
B. Two
c. Three
D. Four
10
209 State whether given statement is True or False.

Does lightning always strike the tallest object?
A. True
B. False

8
210 An inverted image can be seen in a
convex mirror,
A. under no circumstances
B. when the object is very far from the mirror
C. when the object is at a distance equal to the radius of curvature of the mirror
D. when the distance of the object from the mirror is equal to the focal length of the mirror
10
211 What is the basic difference between a
real image and a virtual image?
A. Real image are the image that can be obtained on a screen whereas virtual image cannot be obtained on the screen
B. Virtual image can be obtained on a screen while real images cannot be obtained on a screen
C. Virtual images are formed only in refraction not in reflection while real image can be formed in both
D. Virtual images are formed only in reflection while real image are also only found in refraction
10
212 The heat of sun focussed by a convex lens on a piece of paper is capable of
A. Cooling the paper
B. Just heating the paper
c. Burning the paper
D. Folding the paper
10
213 Which of the following Earth’s plates is responsible for causing an earthquake?
A. The crust of the earth
B. The mantle of the earth
c. The inner core of the earth
D. The outer core of the earth
8
214 Flash-lights make use of
A. convex lenses
B. concave lenses
c. both convex and concave lenses
D. no lenses at all
10
215 On ( 26^{text {th }} ) January, 2001 , a major earthquake occured in district
of Gujarat.
A. Uri
B. Tangdhar
c. Bhu
D. Kachchh
8
216 Lightning is:
A. caused by accumulation of charges in cloud
B. caused by dispersion of charges in cloud
C . caused by rotation of charges in cloud
D. none of the above
8
217 Electric discharges in the atmosphere is associated with natural phenomena
such as :
A. lightning
B. reflecting
c. refracting
D. none of the above
8
218 A beam of light incident on a convex lens parallel to its principal axis converges at a point on the principal axis. Name the point:
A. First focus
B. Second focus
c. First centre
D. Second centre
10
219 Centre point of a lens is called
A. Centre of curvature
B. Pole
c. Origin
D. optical centre
10
220 is the indication to rush
for safer place.
A. Thunder
B. Rain
c. clouds
D. All of the above
8
221 How is lightening beneficial to plants?
A. It brings rain,
B. It increases the amount of nitrates in the soil,
C. It increases the minerals in the soil,
D. It provides the chemical energy required by plants,
8
222 A ray of light parallel to principal axis
after reflection from concave mirror
passes through
10
223 Which lens are used to correct myopia or short sightedness?
A. Convex lens
B. Concave lens
c. Bipolar lens
D. Cylindrical lens
10
224 If a mirror has a focal length of ( -20 mathrm{cm} )
it is a :
A. convex mirror
B. concave mirror
c. plane mirror
D. lens
10
225 The Earth’s crust plates moves
brushing past each other or collide. It
causes:
A . landslides
B. volcanic eruption
c. earthquake
D. none of the above
8
226 The top of the atmosphere is about 400
kV with respect to the surface of the earth, corresponding to an electric field
that decreases with altitude. Near the
surface of the earth, the field is about
( 100 V m^{-1} )
Still, we do not get an electric shock as we step out of our house into the open house, because (assume the house to
be a steel cage so that there is no field inside)
A. There is a potential difference between our body and the ground
B . ( 100 mathrm{Vm}^{-1} ) is not a high electric field so that we do not feel the shock
c. our body and the ground forms an equipotential surface
D. The dry atmosphere is not a conductor
8
227 What happens when the lower end of the lightning conductor is not properly buried in the ground?
A. No earthing
B. Building are protected
c. Damage building and even life
D. Both a &
8
228 The Earth’s surface, the ionosphere and
the atmosphere is known as:
A. global atmosphere electrical circuitt
B. local atmosphere electrical circuit
c. electrical circuit
D. none of these
8
229 Which type of lenses are used in spectacles for the correction of myopia of the eyes?
A. Convex lenses
B. Concave lenses
c. Both convex and concave lenses
D. None of these
10
230 The refractive idea of glass is ( 3 / 2 ) velocity of light in glass would
be
10
231 Assertion
When charges are shared between any
two bodies no charge is really lost some
loss of energy does occurs.
Reason
Some energy disappears in the form of heat, sparking etc.
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
232 Consider a transparent hemisphere ( (n=2) ) in front of which a small object
is placed in air ( (n=1) ) as shown.
Consider a ray starting from ( boldsymbol{O} ) which strikes the spherical surface at grazing
incidence ( (boldsymbol{i}=mathbf{9 0 ^ { circ }}) . ) Taking ( boldsymbol{x}=boldsymbol{R}, ) what
will be the angle (from normal) at which
the ray may emerge from the plane
surface.
( mathbf{A} cdot 90 )
В. ( 0^{circ} )
( c .30 )
( D cdot 60 )
10
233 An small object is kept at ( 18 mathrm{cm} ) from combination of a convex lens and plane
mirror to get the image on object itself. Now the space between lens and mirror is filled with liquid of refractive index
( mu L . ) Now we need to keep the object at
( 27 mathrm{cm} ) to get the image on object. Find
( mu L )
( A )
B.
( c )
2
( D )
10
234 The focal length can be expressed in:
A. metre
B. Dioptre
c. watt
D. Horse power
10
235 Sometimes blurred and less sharply
defined images are formed. This defect
is called
A. Chromatic aberration
B. Spherical aberration
c. Blurred lens
D. None of the above
10
236 Mark the correct statement(s) from the
following for image formation of a real
object.
This question has multiple correct options
A. Image formed by a single convex mirror can be real
B. Image formed by a single convex mirror can be virtual
C. Image formed by a single convex mirror can be magnified
D. Image formed by a single convex mirror can be inverted
10
237 What is the ratio of the speed of light in a vacuum to the speed of light in a particular material is called?
A. The coefficient of diffraction of the materia
B. The index of refraction of the material
c. The coefficient of refraction of the material
D. The index of diffraction of the material
E. The modulus of diffraction of the material
10
238 Refractive index of glass relative to
water is ( 9 / 8 . ) What is the refractive index of water relative to glass?
10
239 Give a brief account of lightning
conductors.
8
240 The air in the path of lightning goes up to a temperature of about
( mathbf{A} cdot 300^{circ} C )
в. ( 3000^{circ} mathrm{C} )
( mathbf{c} cdot 300000^{circ} mathrm{C} )
D. ( 30000^{circ} mathrm{C} )
8
241 A lightning rocket is a device used to
control
A. time and location of a lighting strike.
B. fuel and location of a lighting strike.
C. the lighting of the strom
D. none of the above
8
242 We can burn a piece of paper by focusing the sun rays by using a particular type of lens. Name the type of lens used for the above purpose. 10
243 During lightning which of the following is not a safe place?
A. In car
B. Bus stop
c. Inside a house
D. open field
8
244 The refractive index of glass in
maximum for :
A . red color
B. yellow color
c. violet color
D. green color
10
245 State three points of differences between a real image and a virtual image. 10
246 Which of the following is safest way to protect yourself from lightning?
A. Run to an open field
B. Open an umbrella for cover
c. Take shelter under trees
D. Squat low on ground
8
247 Fill in the blank.
is most commonly caused by charge separation in cumulonimbus clouds, or thunderheads.
A. Strom
B. Lightning
c. cyclone
D. Hurrican
8
248 Which of the following is an example of atmospheric electricity?
A. Auroras
B. Lightening
c. Ionospheric currents
D. All of the above
8
249 Lightning is also known as:
A. Mechanical energy
B. Electric discharge.
c. Potential current
D. Kinetic current
8
250 Which of the following produces virtual image?
A. simple microscope
B. Ordinary camera
c. Projector
D. cinemascope
10
251 Define principal axis of a lens. 10
252 Name the kind of mirror used to obtain
a virtual and enlarged image :
A. Concave Mirror
B. Convex Mirror
c. Plane Mirror
D. All of the above
10
253 Define the term refractive index of a
medium in terms of velocity of light.
10
254 Draw a ray diagram for concave mirror when the object is between center of
curvature and focus
10
255 Absolute refractive index of a
substance is
A. Speed of light in vacuum/Speed of light in medium
B. Speed of light in water/Speed of light in medium
C. Speed of light in medium/speed of light in air
D. Speed of light in medium/speed of light in water
10
256 A point object is placed at the centre of
a glass sphere of radius ( 6 mathrm{cm} ) and
refractive index ( 1.5 . ) The distance of
virtual image from the surface is:
A. ( 6 mathrm{cm} )
в. 4 ст
c. ( 12 mathrm{cm} )
D. 9 ст
10
257 What kind of lens would form an erect
and magnified image?
10
258 A ray of light from air is incident in water; then which property of light will not change in water?
A. Velocity
B. Frequency
c. Amplitude
D. colour
10
259 Lightning is formed in unstable atmospheric zones where there is
typically a lot of and
( mathbf{A} ). Heat, moisture
B. Heat, vapour
c. Heat, gas
D. Heat, lava
8
260 The weak zone around the boundaries of
plates underneath the Earth, which is prone to slide and cause an earthquake is commonly known as:
A. Fault zone
B. Eruption zone
c. Explosive zone
D. Sliding zone
8
261 What are may happen if a building does
not have earthing?
A. Lightning may strike a building due to opposite charge causing fir or damage to the building
B. In the rainy season water increases the chances of lightning striking a building causing damage
C. Both A & B
D. None of the above
8
262 A ray of light passes from ( boldsymbol{A} ) to ( boldsymbol{B} ) & bends towards the normal, comment on
the refractive index of ( A & B )
10
263 The principal axis is also called
of the lens.
A. optical axis
B. x-axis
c. y-axis
D. axis
10
264 Answer the following:
What are the rules used for drawing
ray diagrams for the formation of image by spherical mirror?
10
265 Which scale is used to measure the
magnitude of earthquake?
A. Kelvin
B. Parcal
c. celsius
D. Richter
8
266 Assertion
High energy particles from outer space, on entering the earth’s atmosphere
causes ionisation of the atoms of the
gases present in the atmosphere.
Reason

One goes higher the atmospheric
pressure decreases.
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
267 Fill in the blank:
Air is a/an conductor of
electricity.
A. good
B. poor
c. extremely good
D. neutral
8
268 What causes lightning?
A. Excessive electric charge in the atmosphere
B. Increased chemical energy in the atmosphere
C. Attraction between two oppositely charged clouds
D. All of the above
8
269 Fill in the blanks:
is geometric centre of spherical mirror.
A. Principal force (F)
B. Centre of curvature (C)
c. Pole (P)
D. Secondary focus ( left(F_{2}right) )
10

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