Question

A thin lens is made with a material having refractive index  L = 1.5. Both the sides are convex. It is dipped in water (μ = 1^.33). It will behave like

(a) a convergent lens

(b) a divergent lens

(c) a rectangular slab

(d) a prism.

Answer 1

(a) a convergent lens

EXPLANATION: 

The double convex lens behaves as a convergent lens in the air because the µ of the lens is greater than air. When it is dipped in water its µ is still greater than water hence it will act as a convergent lens.