A convex mirror has a radius of 10 cm. What is its focal length?
A) 10 cm
B) 5.0 cm
C) 20 cm
D) −5.0 cm
E) −10 cm

Question

Quizplus · Accepted Answer

The focal length (f) of a convex mirror is given by the formula f = R/2, where R is the radius of curvature. Since the radius is 10 cm, the focal length is 10/2 = 5 cm. However, for a convex mirror, the focal length is considered positive according to the mirror equation convention, but in the context of sign conventions used in optics, the focal length of a convex mirror is actually considered negative. Therefore, the correct answer is -5.0 cm.

A Convex Mirror Has a Radius of 10 Cm