Question

When light wave passes from a medium of refractive index $ \mu $ to another medium of refractive index $ 2\mu $, the phase change occurs to the light is:

• A. 180°
• B. 90°
• C. 60°
• D. zero

Hint:

When light passes from a medium to another with a refractive index ratio of 1:2, no phase shift occurs, unlike the common 180° phase shift when light reflects off a denser medium.

Answer 1

The Correct Option is D

When a light wave passes from one medium to another, the phase change occurs due to the difference in the refractive indices of the two media. However, if the refractive index of the second medium is twice that of the first, there is no phase change due to the symmetry in the refractive index. In this case, the refractive indices of the first and second media are \( \mu \) and \( 2\mu \) respectively. 
Since no significant phase reversal occurs when transitioning between media with such refractive index ratios, the phase change is \( 0^\circ \).