Question

calculate the power of a lens of focal length -20 cm and determine the nature of the lens​

Answer 1

Answer:

Power of the lens = Reciprocal of focal length

P= 1/-0.2 ( 1D= 1m) ( 1 Diopter is defined as the power of the lens with focal length of 1m)

P= 10/-2

P= -5                                  

Since the power of the lens is negative, the lens is concave lens.

Explanation: