Question

At what distance from a converging lens of focal length 12 cm must an object be placed in order that an image of magnification will be produced.

Answer 1

Answer:

f = 12 cm

m = 1

m = v/u = 1

⇒ v = u

Lens formula : 1/v – 1/u = 1/f

Putting the value of v, u and f,

1/u – 1/-u = 1/12 (image distance is negative)

2/u = 1/12

U = 24 cm

The object should be placed at a distance of 24 cm to from the lens (on the left side).