Question

28. The focal length of a converging lens is 20cm. An object is 60cm from the lens. Where will the
images be formed and what kind of image is it? (AS1) (TQ)
Given: - Focal length, f = 20 Cm​

Answer 1

Answer:

Explanation:

Given :-

Focal length, f = 20 cm

Object distance, u = - 60 cm

To Find :-

Image distance, v = ??

Formula to be used :-

Lens formula,

i.e, 1/f = 1/v - 1/u

Solution :-

Putting all the values, we get

1/f = 1/v - 1/u

⇒ 1/v = 1/f - 1/u

⇒ 1/v = 1/20 - 1/- 60

⇒ 1/v = 3 - 1/60

⇒ 1/v = 2/60

⇒ 1/v = 1/30

⇒ v = 30 cm

Hence, the object distance is 30 cm.

Nature of image - Real and inverted.