Question

The answer should be ?

Answer 1

`sin(90^circ-p)/sin(90^circ -q)= cos p/cos q`

Explanation:

The angles of incidence and refraction that appear in Snell's law are measured from the normal. It is easy to see that they are `90^circ-p` and `90^\circ -q` , respectively.

So, the refractive index of the glass block is

`sin(90^circ-p)/sin(90^circ -q)`