Question

Calculate the critical angle for glass air surface if a ray of light which is nicident ni air on the glass surface is deviated through `15^(@)`, when the angle of incidence is `45^(@)`.

Answer 1

Correct Answer - `45^@`
Here, `i= 45^@, r = 45^@ - 15^@ = 30^@`
`mu = (sin i)/(sin r) = (sin 45^@)/(sin 30^@) = (1)/(sqrt(2)) xx 2 = sqrt(2)`
`sin C = (1)/(mu) = (1)/(sqrt(2))`
`:. C = 45^@`.