ABHYAS | Self Learning | Testing Platform

Q.1

Which one of the following denotes the unit of power of a lens ?

A.

Metre

B.

Dyne

C.

Diopter

D.

None of the above

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Q.2

When white light is passed through prism, it splits into ______________-

A.

Eight colour

B.

Nine colours

C.

Seven colours

D.

Five colours

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Q.3

Sunlight is :

A.

Red in colour

B.

Yellow in colour

C.

Orange in colour

D.

White in colour

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Q.4

In a convex mirror, the object lies between pole and infinity. The image formed is

A.

Behind the mirror

B.

Diminished in size

C.

Virual and erect

D.

All of these

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Q.5

The light that is reflected from a Compact Disc (CD) consists of ______________

A.

Three colours

B.

Seven colours

C.

Four colours

D.

Only Green

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Q.6

A tank of water appears to be less deep than it actually is due to

A.

reflection of light

B.

refraction of light

C.

high refractive index of water

D.

low refractive index of air

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Q.7

An object is placed at infinity in front of a convex lens of focal length 15 cm. The image formed is at _______________

A.

infinity

B.

10 cm

C.

20 cm

D.

15 cm

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Q.8

A Match the entries given in Column - I with those in Column - II.

Column I	Column II
a. Plane mirror	1. Used as a magnifying glass
b. Convex mirror	2. Can form images of objects spread over a large area
c. Convex mirror	3. Used by dentists to see enlarged images of teeth
d. Concave mirror	4. Image is erect and of the same size as the object
e. Concave lens	5. The image is erect and smaller than the object

A.

a-4, b-2, c-1, d-3, e-5

B.

a-4, b-5, c-1, d-3, e-2

C.

a-4, b-3, c-2, d-5, e-1

D.

a-4, b-1, c-3, d-2, e-5

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Q.9

A rainbow is formed due to _____________ of sunlight by water droplets.

A.

Refraction

B.

Reflection

C.

Dispersion

D.

Scattering

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Q.10

Assertion : The air bubble shines in water.

Reason : Air bubble in water shines due to refraction of light.

A.

If both Assertion and Reason are correct and Reason is the Correct explanation of Assertion.

B.

If both Assertion and Reason are correct, but Reason not the Correct explanation of Assertion.

C.

If Assertion is correct but Reason in incorrect

D.

If Assertion is Incorrect but Reason in correct

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Q.11

Suppose we have three lenses of powers P1, P2 and P3 respectively which are placed in close contact with each other. Then the total power of their combination (P) will be :

A.

P1 - P2 - P3

B.

P1 X P2 X P3

C.

P1 + P2 + P3

D.

(P1 + P2) X P3

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Q.12

In which of the pairs of media is reflection possible?

A.

Air to water

B.

Glass to water

C.

Both (A) and (B)

D.

None of these

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Q.13

A thin lens and a spherical mirror have a focal length of +15 cm each. Then

A.

Both are convex

B.

The lens is convex and the mirror is concave

C.

The lens is concave and the mirror is convex

D.

both are concave

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Q.14

Choose the correct statment

A.

When a ray of light moves into an optically denser medium from an optically rarer medium . then it bends away from the normal

B.

A medium in which light travels at slow speed is called optically rarer medium

C.

Light will bend away from the normal as a ray travels from a denser medium to a rarer medium

D.

A medium in which light travels at faster speed is called optically denser medium

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Q.15

If the refractive index of some medium is 'n' then the speed of light in that medium is

A.

n times that in vacuum

B.

1/n times that in vacuum

C.

equal to that in vacuum

D.

2/n times that in vacuum

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Attention !!!!!