Question

It is required to throw an image, magnified two times, on a screen placed at a distance of 6 cm from the object. Find the focal length and nature of the lens required.

Answer 1

Answer:

focal length is - 12 cm and nature of lens is concave lens

Explanation:

magnified two times this m=2

and u=-6 cm so v/u =2

so image distance v becomes -12 cm

thus by calculating the focal length by 1/f =1/v-1/u.

so the focal length become- 12 cm

and the lens become concave lens.