A card shee

Given:

Area of each square, A = 1 mm²

Object distance, u = −9 cm

Focal length of a converging lens, f = 10 cm

(a) Applying the lens formula we have:

…(1)

Where, f₀ = focal length of the objective lens

v₀ = Distance of image formation

u₀ = Distance of object from objective

The lens formula for the image distance v, can be written as:

…(2)

By putting available values in equation (2) we get,

⇒ V₀ = -90 cm

Magnification, m = v/u

m = −90/−9

m = 10

Therefore, area of each square in the virtual image = (10)² A

= 10² x 1 = 100 mm²

= 1 cm²

(b) The lens has a magnifying power of = d/ |u|

= 25/9

= 2.8

(c) The magnification in (a) is not the same as the magnifying power in (b). Both the quantities will be same once the image is formed at the near point (25 cm)