An object is placed 5 cm from the pole of a concave mirror. if the focal length of the mirror is 10 cm. what is the image distance?
- 10 cm in front of the mirror.
- 5 cm in front of the mirror
-
10 cm behind the mirror
- 5 cm behind the mirror
The correct answer is: C
Explanation
u = 5 cm , f = 10 cm, v = ?
(1)/v + (1)/u = (1)/f
(1)/v + (1)/5 = (1)/10
= (1)/v = (1)/10 - (1)/5
= (1 - 2)/10 = (1)/10
∴ v = - 10 cm
∴ The image is 10 cm behind the mirror
There is an explanation video available .