Question

A single lens is mounted in a tube. A parallel beam enters the tube and emerges out of the tube as a divergent beam. Can you say with certainty that there is a diverging lens in the tube?

Answer 1

Explanation:

I can' t say with certainly that there a diverging lens

Answer 2

It can not be said with the certainty that that the tube has a diverging lens.

• On assuming that the tube is in air, with the lens made up of a material with the refractive index as μ>1, it can not be concluded with a certainty that inside the tube there is a divergent lens or a concave lens.
• A converging lens or the convex lens that has its focal point, inside the tube will let the beam emerge out as the diverging beam