Question

How we calculate angle of incidence if the ray of light striking the glass at an angle of 50 degrees slab?

Answer 1

Hey Friend,

The angle which the ray of light makes with the glass slab is called the 'glance angle of incidence'.

Glance angle of incidence = 50 degrees
 
We know,
glance angle + angle of incidence = normal angle
50 + i = 90
i = 40 degrees

Therefore, the angle of incidence is 40 degrees

Hope it helps!