Question

if the angle of incidence of light on a glass slab is 30 degree then what is the angle of refraction

Answer 1

We know that Refractive Index is the ratio if sines of angle of incidence to angle of refraction. That is,

Refractive Index = Sin i / Sin r

So given that, Refractive Index is √3 and sin r is 30°

=> √3 = Sin i / Sin 30

=> √3 * Sin 30 = Sin i

=> √3 * 1 / 2 = Sin i

=> Sin i = √3 / 2

We know that, Sin 60 is √3 / 2. Hence,

Sin i = Sin 60

=> i = 60°

Hence the angle of incidence is 60°.

Answer 2

Refractive index = sin i / sin r

( refractive index of glass = 1.5)

=> 1.5 = sin 30°/ sin r

=> sin r = 1/2 × 2/3

=> sin r = 1/3

=> r = 20° (approx.)