Question

A convex lens made of material of refractive index $n_1$ is placed inside two liquids of refractive indices $n_2$ and $n_3$ as shown . $(n_2>n_1>n_3)$. Parallel beam of light is incident on it. The lens will give rise to

• A. single convergent beam
• B. two different convergent beams
• C. two different divergent beams
• D. a convergent and a divergent beam

Answer 1

Answer: (D)

As $n_2>n_1$, upper part of lens behaves as a divergent lens. So, parallel beam diverges through this part.
As $n_1>n_3$, lower part of convex lens remains as a converging lens. So, parallel beam converges at a point through this part.