Question

An object 4 cm in size is placed at 25 cm in front of a concave mirror of focal length 15 cm. At what distance from the mirror should a screen be placed in order to obtain a sharp image? Find the nature and size of image.

Answer 1

focal length = f = - 15 cm

object distance = u = -25 cm

image distance = v = ?

h_i = ?

h_o =  4 cm

Mirror formula,

Thus, to get image of object sharp it has to be placed at 37.5 cm

Size of image is 6 cm