Question

A concave lens produces an image 20 cm from the lens of an object placed 30 cm from the lens. The focal length of the lens is:; A. 50 cm; B. 40 cm; C. 60 cm; D. 30 cm

Answer 1

Answer:

Option A 50 cm hona chaiye

Answer 2

Answer:C : 60 cm

Explanation:v=- 20cm

U= -30cm then by using lens formula you will get the answer so,the focal length will be -60cm