Multiple choice

A coin is dropped at refractive index of 4/3. The real depth of coin is 28 cm. The coin would be apparently appear to be at the depth of

  1. 80 cms

  2. 25 cms

  3. 20 cms

  4. 21 cms
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

When light travels from a denser medium (water) to a rarer medium (air), it bends away from the normal, making objects appear shallower. The apparent depth is calculated by dividing the real depth by the refractive index: 28 cm ÷ (4/3) = 21 cm. Option A (80 cm) incorrectly multiplies by the refractive index, while B (25 cm) and C (20 cm) are calculation errors.

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