James 30 Aug 2017 - 2


A light ray travels from a Perspex block into the air.

The critical angle of Perspex is 42.9o

What is the angle of refraction when the angle of incidence is 36.0o?

A) 23.6o

B) 24.5o

C) 52.9o

D) 59.7o


In order to calculate the angle of refraction, the refractive index of Perspex has to be found first.

Using the critical angle,


Now that the refractive index of Perspex is known, the angle of refraction can be calculated.


The answer is D.