Question

The image of a candle flame placed at a distance of 30 cm from a mirror is formed on a screen placed in front of the mirror at a distance of 60 cm from its pole. What is the nature of the mirror ? Find its focal length. If the height of the flame is 2.4 cm, find the height of its image. State whether the image formed is erect or inverted.

Answer 1

The nature of the mirror is concave since the image formed is real.

Object distance, u = -30cm

Image distance, v = -60cm

Using mirror equation:

Hence, the focal length of the concave mirror is 20 cm.

Magnification:

where

h_i  = Height of image

h_o = Height of object

Thus, the image height is 4.8 cm.

Image formed by the mirror is inverted.