Question

An object is placed in front of a concave mirror of focal length 12 cm. If distance of the object from the pole of the mirror is 8 cm, then use mirror formula to determine the position of the image formed. Draw a labelled ray diagram to justify your answer in this case.

Answer 1

Mirror formula: 

`1/f = 1/v - 1/u`

Given: `f` = − 12 cm and `u` = 8 cm

`1/v = 1/f - 1/u`

`1/v = (-2)/24 - 3/24`

`1/v = (-5)/24`

`v = (-24)/5`

= − 4.8 cm

The negative sign indicates that the image is formed on the same side as that object.