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)20 cm behind the mirror
B)20 cm in front of the mirror
C)6.7 cm behind the mirror
D)6.7 cm in front of the mirror

Question

Quizplus · Accepted Answer

Using the mirror formula:
1/f = 1/do + 1/di
where f is the focal length (20 cm), do is the object distance (-10 cm) and di is the image distance.

Substituting the given values, we get:
1/20 = 1/-10 + 1/di
Solving for di, we get:
di = -6.7 cm

The negative sign indicates that the image is virtual (behind the mirror) and right-side up. Therefore, the correct choice is C) 6.7 cm behind the mirror.

A Convex Spherical Mirror Has a Focal Length of Magnitude