Question

a piece of black paper, a hole gets burnt in the black paper, after some time.
When a spherical lens is held towards the Sun and a sharp image is formed on

(b) What name is given to the distance between the spherical lens and the black
paper?​

Answer 1

The distance between the spherical lens and the black paper is known as the focal length and the lens is concave lens.

Answer 2

Explanation:

sorry don't know the answer for your question