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MCQ practice · SSC Physics Board questions · Chapter 8: Reflection of Light

Barishal Board 2023 Cumilla Board 2021

A red rose looks red because-

  1. i. it reflects only the red colour
  2. ii. it absorbs all colours except red
  3. iii. the wavelength of red light is longer

Think it through first, then pick an option.

  1. a i and ii
  2. b ii and iii
  3. c i and iii
  4. d i, ii and iii
Answer and explanation

Correct answer: a i and ii

i true: The rose absorbs every colour but red, so only red is in the reflected light; this is part of the reason. ii true: Of all the colours in white light the rose absorbs everything except red; this is the other part of the reason. iii false: Red light does have the longer wavelength, but the rose looks red because of absorption and reflection, not because of the wavelength.

Why the other options are wrong

  • b ii and iii: This is not the answer; the right combination is i and ii. i true: The rose absorbs every colour but red, so only red is in the reflected light; this is part of the reason. ii true: Of all the colours in white light the rose absorbs everything except red; this is the other part of the reason. iii false: Red light does have the longer wavelength, but the rose looks red because of absorption and reflection, not because of the wavelength.
  • c i and iii: This is not the answer; the right combination is i and ii. i true: The rose absorbs every colour but red, so only red is in the reflected light; this is part of the reason. ii true: Of all the colours in white light the rose absorbs everything except red; this is the other part of the reason. iii false: Red light does have the longer wavelength, but the rose looks red because of absorption and reflection, not because of the wavelength.
  • d i, ii and iii: This is not the answer; the right combination is i and ii. i true: The rose absorbs every colour but red, so only red is in the reflected light; this is part of the reason. ii true: Of all the colours in white light the rose absorbs everything except red; this is the other part of the reason. iii false: Red light does have the longer wavelength, but the rose looks red because of absorption and reflection, not because of the wavelength.