Question

Refractive indices of water an glass are `4//3 and 3//2` respectively. A ray of light travelling in water is incident on the water glass interface at `30^@`. Calculate the angle of refraction.

Answer 1

Here, `.^(a)mu_(w) = (4)/(3), .^(a)mu_(g) = (3)/(2)`
`.^(w)mu_(g) = (.^(a)mu_(g))/(.^(a)mu_(w)) = (3//2)/(4//3) = (9)/(8)`
Angle of incidence in water, `I = 30^(@), r = ?`
`(sin i)/(sin r) = .^(w)mu_(g) = (8)/(9)sin I = (8)/(9)sin 30^(@) = (8)/(9) xx (1)/(2)`
`sin r = 0.4444`
`r = sin^(-1)0.4444 = 26.38^(@)`