Question

2. The wave front shown at the left for light in air reaches the plane surface (shown by a slanted line) that bounds a medium with n 1.50 Which diagram below correctly shows the wave front while entering the medium at the right? A C D E

Is my understanding right?

The first perpendicular line is the wavefront (not the ray of light), and the second slanted line is the surface.

Rays of light are always perpendicular to the wavefront, and the ray of light bends towards the normal when it passes from rarer medium to the denser medium,

therefore, the answer should be C.

Answer 1

Yah! You are right .Wave front normally incident on surface ,using Snell's law--. n₁sin$\theta$₁=n₂sin$\theta$₂

Here $\theta$₁= 90° & n₁=1

$\theta$₂=? & n₂= 1.5

So putting values.

sin$\theta$₂=2/3 => $\theta$₂ = 41.8°

Light bends to the normal.

So option c is correct.