Question

What is the angle between incident ray and emergent Ray in case of rectangular glass slab

Answer 1

angle b/w incident ray and emergent ray is 45 degrees

Answer 2

The angle of emergent ray and incident ray in rectangle shaped glass slab are parallel.

As the incident ray falls on the first surface of the rectangular glass, it makes a refractive angle according to refractive index of that material which here is glass.

Then the ray emerges from the glass slab in rectangular shape from the other surface and therefore the angle of incident ray and emergent rays are nearly parallel and thus doesn't make an angle between them.