Question

The image of a candle flame placed at a distance of 45 cm from a spherical lens is formed on a screen placed at a distance of 90 cm from the lens. Identify the type of lens and calculate its focal length. If the height of the flame is 2 cm, find the height of the image.

Answer 1

Nature of Spherical lens = Convex 

Given u = -45 cm, v = +90 cm, h₁, =+2cm

Using lens formula

So, the height of the image is -4 cm. The negative sign indicates that it is formed below the principal axis.