When a CD (compact disc used in audio and video systems) is seen in sunlight, rainbow-like colours are seen. This can be explained on the basis of the phenomenon of:
✓ Correct answer: d) refraction, diffraction and transmission
ExplanationIn the case of a compact disc (CD), when sunlight or any other light source hits its surface, the following optical phenomena occur.Diffraction: The CD’s surface contains tiny, closely spaced grooves that act like a diffraction grating.This causes the light to spread out into different colors, creating the rainbow effect that is visible.Refraction: Light also passes through the transparent plastic layer of the CD, and as it enters and exits this layer, it bends due to the change in the refractive index between the plastic and air.Transmission: Some light also passes through the CD material, further contributing to the observed effects.Together, these phenomena—refraction, diffraction, and transmission—combine to produce the beautiful rainbow-like colors seen when a CD is viewed in sunlight.268
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