An object is placed at a distance of `40 cm` from a concave mirror of focal length `15 cm`. If the object is displaced through a distance of `20 cm` towards the mirror, the displacement of the image will be

Options

A. 30 cm away from the mirror
B. 36 cm away from the mirror
C. 30 cm towards the mirror
D. 36 cm towards the mirror

Answer

B

Explanation

`v_(2) =(uf)/(u-f) = ((-20)(-15))/(-20 + 15) = -60 ` cm
Displacement of image = `v_(2) - v_(1) = -36 ` cm