Question

1. Take a convex lens and hold it over a sheet of paper in sunlight.
2. Now, move the lens in such a way that there is a tiny spot of light on the paper.
3. Hold the lens in this position for a while. What happens?

Answer 1

When the convex lens is held in sunlight and adjusted to form a tiny bright spot on the paper, the lens concentrates the Sun’s rays at one point. After holding it in this position for some time, the paper at that spot becomes very hot and may start burning or get charred.

This happens because the convex lens brings the Sun’s rays together at its focus. Thus, solar energy is converted into heat energy at the small bright spot.