A prism having an apex angle `4^(@)` and refractive index 1.5 is located in front of a vertical plane mirror as shown in figure. Through what total angle is the ray is deviated after reflection from the mirror ?

Options

A. `176^(@)`
B. `4^(@)`
C. `178^(@)`
D. `2^(@)`

Answer

C

Explanation

`delta_(1) = 4(1.5-1) = 2^(@)Cw`
`delta_(2) = 180 - 2 xx 2 = 176^(@)Cw`
`delta = delta_(1) +delta_(2)`
`delta = 178 Cw`