passwella.
Menu

JAMB Physics 1982 Question 8

Question 8

Refraction of Light

The speed of light in air is 3.00 × 108 m s−1. Its speed in glass having a refractive index of 1.65 is

  1. A.1.65 × 108 m s−1
  2. B.3.00 × 108 m s−1
  3. C.4.95 × 108 m s−1
  4. D.1.82 × 108 m s−1
  5. E.6.00 × 108 m s−1.
Show the answer and explanation

Answer: D (1.82 × 108 m s−1)

Explanation

Speed in glass = speed in air ÷ refractive index = 3.00 × 108 ÷ 1.65 ≈ 1.82 × 108 m s−1.