Practice test

Light and optical instruments - Test Set 4

Review 20 exam-focused questions with detailed explanations, then start the interactive test when you are ready.

20 questions

Questions and explanations

  1. Question 1

    On a rainy day small oily films on water show brilliant colour. This is due to -
    1. Interference
    2. Polarization
    3. Dispersion
    4. Scattering
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  2. Question 2

    An optically plane surface reflects a beam of light
    1. As a diffused beam in one direction
    2. As a parallel beam in one direction
    3. As diffused beams in all directions
    4. As parallel beams in all direction
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  3. Question 3

    When white light is passed through a glass prism, which of the following colours is refracted the most?
    1. Blue
    2. Red
    3. Orange
    4. Violet
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  4. Question 4

    A person is moving towards a plane mirror with a speed of 1 m/sec. The image will approach the moving person with a relative speed of
    1. 1.5 m/sec.
    2. 1 m/sec.
    3. 2 m/sec.
    4. 3 m/sec.
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  5. Question 5

    If the focal length of the objective of an astronomical telescope increases, then its magnifying power will
    1. Increase
    2. Decrease
    3. Remain the same
    4. Cannot be predicted
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  6. Question 6

    When an object is placed between two parallel mirrors, the number of images formed will be
    1. Eight
    2. Two
    3. Thirty Two
    4. Infinite
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  7. Question 7

    Focusing in a camera is carried out by varying
    1. The amount of light
    2. The distance of the lens from film
    3. The distance of the lens from the object
    4. The speed of the shutter
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  8. Question 8

    Bats can fly in the dark without hitting objects because
    1. They are flying mammals
    2. Their night vision is good
    3. They are guided by ultrasonic waves which they produce
    4. Of no scientific reason
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  9. Question 9

    The closest distance at which a normal person can see an object clearly is
    1. 10 cm.
    2. 50 cm.
    3. 80 cm.
    4. 25 cm.
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  10. Question 10

    Some automobiles have additional yellow headlights. This is so because
    1. Yellow light consumes less power
    2. Yellow light does not produce a dazzling effect in the eyes of the pedestrians
    3. Yellow light is able to penetrate fog, thus it is able to illuminate the road better in foggy nights
    4. The automobile looks more imposing with yellow headlights
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  11. Question 11

    The following animal has similar vision as we have
    1. Goat
    2. Owl
    3. Horse
    4. Pigeon
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  12. Question 12

    The blue colour of the sky is due to
    1. Scattering
    2. Refraction
    3. Reflection
    4. Dispersal
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  13. Question 13

    Which one will you use to correct myopic vision?
    1. Sphero-cylindrical lens
    2. Concave lens of suitable focal length
    3. Convex spectacle lens of suitable length
    4. Convex lens of proper power
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  14. Question 14

    The production of shadow proves that
    1. Light does not diffract
    2. Light is a type of particle
    3. Light is an electromagnetic wave
    4. Light travels approximately in straight lines
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  15. Question 15

    If red light is used to illuminate a green leaf and a red flower, it will appear as
    1. Green leaf and red flower
    2. Red leaf and red flower
    3. Black leaf and red flower
    4. Black leaf and black flower
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  16. Question 16

    A magnifying glass or a simple microscope produces a
    1. Magnified real image
    2. Virtual image near the eye, having the same size as the object
    3. Diminished virtual image
    4. Magnified virtual image
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  17. Question 17

    Both ends of the tube of a Telescope have
    1. Convex lens
    2. Concave lens
    3. Plano-convex lens
    4. Plano-concave lens
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  18. Question 18

    Dentists use
    1. Special Mirror
    2. Plane Mirror
    3. Concave Mirror
    4. Convex Mirror
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  19. Question 19

    When the angle of incidence is equal to the critical angle for the media, the angle of refraction is
    1. 0°
    2. 90°
    3. 45°
    4. Angle of incidence
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  20. Question 20

    Hubble is a
    1. Nuclear weapon
    2. Musical instrument
    3. Space telescope
    4. Star
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