Question

A beam of light travelling to the principal axis of a concave lens appears to diverge from a point 20 CM behind the lens after passing through the lens find the power of the lens​

Answer 1

Answer:

p=1/f

Explanation:

use this formula to calculate the power.it is 10 according to your question

Answer 2

Answer: -5D

Explanation: 20cm is the focal length of concave lens. ( F=-0.2m)

By using : p=1/f.

P=1/-0.2.

P=-5D