Question

what are the precautions to be taken in the experiment to find the vertical shift of a glass slab​

Answer 1

Explanation:

The light rays from an object at the bottom of the slab, water glass, or pond are bent at the surface of water or glass and are bent away from the normal at the point of incidence. So for a viewer an object at the bottom of a denser medium appears to be raised upwards. This is called the vertical shift