Question

One side of a glass slab is silvered as shown in the figure. A ray of light is incident on the other side at angle of incidence `45^@.` Refractive index of glass is given as `sqrt2`. The deflection suffered by the ray when it comes out of the slab is

A. `90^@`
B. `180^@`
C. `120^@`
D. `45^@`

Answer 1

Correct Answer - A
`mu=sin i/sin r rArr sqrt2=sin45^@/sin r or r=30^@`

`delta_(Total)=delta_A-delta_B+delta_C`
`=(45^@-30^@)-[180^@-2(30^@)]+(45^@-30^@)`
`=-90^@ or |delta_(Total)|=90^@`