Question

if Power of lens is -2.5 D find the nature of lens and focal length

Answer 1

Answer:

- 40cm

Explanation:

Given ,

Power of lens , P = -2.5 D

Therefore ,

focal length , f = 1 / p = 1 / -2.5 m

= - 40 cm

The negative sign of focal length indicates that the lens is concave.