Question

The above lens has a focal length of 10 cm. The object of height 2 mm is placed at a distance of 5 cm from the pole. Find the height of the image.

Options

• 4cm

• 6.67mm

• 4mm

• 3.33mm

Answer 1

4mm

Explanation:-

f = +10cm (Convex lens)

h₁= 2mm = 0.2cm

u = -5cm

`1/f=1/v-1/5`

`1/v=1/10-1/5`

`(1-2)/10=(-1)/10`

V = -10cm

`"m"=v/u=h_2/0.2`

⇒ h₂ = 0.4cm

h₂ = 4mm