The Brewster angle for the glass air interface is `54.74^(@)` if a ray of light going from air to glass strikes at an angle of incidence `45^(@)` then the angle of refraction is

Options

A. `60^(@)`
B. `30^(@)`
C. `25^(@)`
D. `54.74^(@)`

Answer

B

Explanation

According to the Brewster `mu = tan i_(p)`
`mu = tan 53.74`
`mu = sqrt(2)`
`therefore sqrt(2) = (sin i)/(sin r) rArr sqrt(2) = (sin 45^(@))/(sin r)`
`sin r = (1)/(sqrt(2)) xx (1)/(sqrt(2)) = (1)/(2)`
`r = sin^(-1)((1)/(2))`
`r = 30^(@)`