Question

Draw a ray diagram to show that the depth of a vessel cotaining water when seen from above, appears to be less than its real depth.

Answer 1

The depth of a vessel containing water when seen from above, appears to be less than its real depth because a ray of light from the bottom of the vessel is incident normally on the water-air surface.

It travels straight in air. Another ray incident from water on the surface, when passes to air, bends away from the normal, The two refracted rays when produced back, meet at the image of object.

Thus, to the observer in air, the depth of the vessel appears to be AI instead of AO, due to refraction of light from water to air. The apparent depth AI is less than the real depth AO.