Practice test

Light and optical instruments - Test Set 5

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

    The surface of water in a lake is going to freeze. The temperature of water at the bottom is
    1. 4°C
    2. Less than 4°C
    3. 0°C
    4. More than 4°C
    View explanation

    Sign In to See Explanations. Sign Up Here

  2. Question 2

    The screen of a cinema hall is always white and rough. Because light rays of all colours falling on the screen suffer
    1. Total absorption
    2. Total reflection
    3. Refraction
    4. Scattering
    View explanation

    Sign In to See Explanations. Sign Up Here

  3. Question 3

    The primary colours of light are
    1. Red, Green, Blue, Yellow
    2. Red, Blue, Green
    3. Yellow, Blue, Red, Grey
    4. None of the above
    View explanation

    Sign In to See Explanations. Sign Up Here

  4. Question 4

    The viewfinder of a motor car is a
    1. Plane mirror
    2. Concave mirror
    3. Convex mirror
    4. Convex lens
    View explanation

    Sign In to See Explanations. Sign Up Here

  5. Question 5

    The minimum distance between an object and its real image in a convex lens is
    1. More than 4f
    2. Less than 4f
    3. Equal to 4f
    4. Equal to 2f
    View explanation

    Sign In to See Explanations. Sign Up Here

  6. Question 6

    A clear piece of glass immersed in glycerol cannot be seen separately because, compared to the refractive index of glycerol, the refractive index of glass is
    1. Greater
    2. Lesser
    3. Nearly equal
    4. This does not depend on refractive index
    View explanation

    Sign In to See Explanations. Sign Up Here

  7. Question 7

    Optical fiber works on the
    1. Principle of Refraction
    2. Total Internal Reflection
    3. Scattering
    4. Reflection
    View explanation

    Sign In to See Explanations. Sign Up Here

  8. Question 8

    Which one of the following reflects back more sunlight as compared to other three?
    1. Sand desert
    2. Prairie land
    3. Land covered with fresh snow
    4. Paddy crop land
    View explanation

    Sign In to See Explanations. Sign Up Here

  9. Question 9

    Purpose of an optical fibre is to
    1. Reflect light of different colours
    2. Dispense light into component colours
    3. Refract light of different colours
    4. Transmit light of different colours
    View explanation

    Sign In to See Explanations. Sign Up Here

  10. Question 10

    The Phenomenon which causes mirage is
    1. Total Internal Reflection
    2. Polarization
    3. Diffraction
    4. Interference
    View explanation

    Sign In to See Explanations. Sign Up Here

  11. Question 11

    Total Internal Reflection can not take place when light goes from
    1. Glass to water
    2. Water to Glass
    3. Water to air
    4. Glass to air
    View explanation

    Sign In to See Explanations. Sign Up Here

  12. Question 12

    Optical fibre works on the principle of
    1. Scattering
    2. Refraction
    3. Total Internal Reflection
    4. Interference
    View explanation

    Sign In to See Explanations. Sign Up Here

  13. Question 13

    Energy in reflected light is
    1. Does not depend on the angle of incidence
    2. Become maximum for an angle of incidence of 45°
    3. Decrease with increase in angle incidence
    4. Increases with increase in angle
    View explanation

    Sign In to See Explanations. Sign Up Here

  14. Question 14

    Which of the following optical phenomena is responsible for the brilliance of diamond?
    1. Total Internal Reflection
    2. Total surface Reflection
    3. 100% transmission
    4. Maximum Refraction
    View explanation

    Sign In to See Explanations. Sign Up Here

  15. Question 15

    The phenomenon of change in direction of light when it passes from one medium to another is called
    1. Propagation
    2. Refraction
    3. Reflection
    4. Dispersion
    View explanation

    Sign In to See Explanations. Sign Up Here

  16. Question 16

    Which of the following is not caused by atmospheric refraction?
    1. Sun becoming visible two or three minutes before actual sunrise.
    2. Twinkling of stars at night
    3. Sun appearing red at sunset
    4. Sun appearing higher in the sky than it actually is
    View explanation

    Sign In to See Explanations. Sign Up Here

  17. Question 17

    A star appears twinkling in the sky because of
    1. Scattering of light by atmosphere
    2. Diffraction of light by atmosphere
    3. Reflection of light by atmosphere
    4. Refraction of light by atmosphere
    View explanation

    Sign In to See Explanations. Sign Up Here

  18. Question 18

    A water tank appears shallower when it is viewed from top due to
    1. Refraction
    2. Total Internal Reflection
    3. Reflection
    4. Rectilinear propagation of light
    View explanation

    Sign In to See Explanations. Sign Up Here

  19. Question 19

    The reason for a swimming pool to appear less deep than the actual depth is
    1. Light scattering
    2. Refraction
    3. Interference
    4. Reflection
    View explanation

    Sign In to See Explanations. Sign Up Here

  20. Question 20

    A plane glass slab is kept over coloured letters which appears least raised is –
    1. Red
    2. Green
    3. Violet
    4. Blue
    View explanation

    Sign In to See Explanations. Sign Up Here