A convex spherical mirror has a focal length of magnitude 20 cm. If an object is placed 10 cm in front of the mirror on the mirror's axis, where is the image located?
A) 6.7 cm in front of the mirror
B) 6.7 cm behind the mirror
C) 20 cm in front of the mirror
D) 20 cm behind the mirror

Question

Quizplus · Accepted Answer

For a convex mirror, the focal length is negative. Using the mirror formula (1/f = 1/v + 1/u), where f = -20 cm and u = -10 cm, we find v = -6.7 cm, indicating the image is 6.7 cm behind the mirror.

A Convex Spherical Mirror Has a Focal Length of Magnitude