Find the focal length of a lens of power -2.0 D. What type of lens is this?

5 views

1 Answers

Given Power P =- 2.0D
If f is the focal length of lens, then P =1/f gives

f=1/P=1/-2.0 m=-50cm
Negative sign shows that lens is concave. Thus focal length oflens is 50 cm and it is concave lens.

5 views