A diverging beam of light from a point source S having divergence angle `alpha`, falls symmetrically on a glass slab as shown. The angles of incidence of the two extreme rays are equal. If the thickness of the glass slab is t and the refractive index n, then the divergence angle of the emergent beam is

Options

A. Zero
B. `alpha`
C. `sin^(-1)(1//n)`
D. `2sin^(-1)(1//n)`

Answer

B

Explanation

Since rays after passing through the glass slab just suffer lateral displacement hence we have angle between the emergent rays as `alpha`