Question

A ray of light is travelling is travelling from air to water. What is the angle of incidence in air, if angle of refraction in water is `41^(@)` ? Take refractive index of water `= 1.32`.

Answer 1

Correct Answer - `60^(@)`
Here, `i= ?, r = 41^(@) .^(a)n_(w) = 1.32`
From `.^(a)n_(w) = (sini)/(sinr)`,
`sini = .^(a)n_(w) xx sinr = 1.32 xx sin41^(@) = 1.32 xx 0.6561 = 0.8660`
Using tables of natural sines , `i= 60^(@)`