Question

An object OA is placed in front of the concave mirror as given in the image. The point F is the focus of the mirror and P is the pole. Determine the distance of the image from the pole of the concave mirror.
66.66 cm
50 cm
33.33 cm
20 cm​

Answer 1

33.33cm

The correct option is C 33.33 cm

Given, object distance u=−50 cm  (Using sign convention)

Let the image distance be v.

Focal length, f=−20 cm

Using the mirror formula

1v+1u=1f1v+1−50=1−201v=1−20−1−501v=1−20+1501v=1−20×55+150×221v=−5100+21001v=2−51001v=−3100v=−1003v=−33.33 cm 

(Negative sign indicates that the image is formed in front of the mirror)