Question

Refractive index ______ with increase in temperature of medium.

• A. increases
• B. decreases
• C. remains same
• D. cannot say

Answer 1

The correct option is B decreases

As temperature increases, the density of medium decreases and hence refractive index decreases. Light is propagated by absorption and re-emission. Thus, as density decreases light travels faster and refractive index decreases.
$\frac{n_1}{n_2}=\frac{v_2}{v_1}$