JAMB Physics 1994 Question 34

Question 34

Refraction of Light

Light of frequency 6.0 × 10¹⁴ Hz travelling in air is transmitted through glass or refractive index 1.5. Calculate the frequency of the light in the glass.

A.4.0 × 10¹⁴ Hz
B.6.0 × 10¹⁴ Hz
C.7.5 × 10¹⁴ Hz
D.9.0 × 10¹⁴ Hz

Show the answer and explanation

Answer: B (6.0 × 10¹⁴ Hz)

Explanation

Frequency is set by the source and does not change on refraction; only the speed and wavelength fall by the factor 1.5. So it stays 6.0 × 10¹⁴ Hz.