Question

how can we prove refraction of light using glass slab and pins​

Answer 1

Explanation:

When a beam of light falls obliquely at the interface of the two optical media, direction of its path changes when it enters into the other medium. This phenomenon exhibited by the light rays is called refraction of light. This is due to the change in speed of light while going from one medium to the other.

Answer 2

efraction through a rectangular glass slab and principle of reversibility of light:

Consider a rectangular glass slab, as shown in figure. A ray AE is incident on the face PQ at an angle of incidence i. On entering the glass slab, it bends towards normal and travels along EF at an angle of refraction r. The refracted ray EF is incident on face SR at an angle of incidence r’. The emerged ray FD bends away from the normal at anangle of refraction e.

Thus the emergent ray FD is parallel to the incident rays AE, but it has been laterally displaced with respect to the incident ray. There is shift in the path of light on emerging from a refracting medium with parallel faces.