A concave mirror has a radius of 2.0 m. What is the refractive power of a lens of the same focal length as the mirror?
A) 0.50 D
B) 1.0 D
C) 2.0 D
D) 0.75 D
E) −0.50 D

Question

Quizplus · Accepted Answer

The focal length of a concave mirror is half of its radius, so the focal length of this mirror is 1.0 m. The refractive power of a lens is given by the formula P = 1/f, where P is the power in diopters and f is the focal length in meters. Therefore, the power of a lens with the same focal length as the mirror is P = 1/1.0 m = 1.0 D.

A Concave Mirror Has a Radius of 2