Question

When an object is located 32 cm to the left of the lens, the image is formed 17 cm to the right of the lens. What is the focal length of the lens?

Answer 1

Answer: 11.1cm

Step-by-step explanation:

Object distance (u) = 32cm

Image distance(v) = 17cm

Focal length(f) =?

Lens formular:

1/f = 1/u + 1/v

1/f = 1/32 + 1/17

Taking the L. C. M of 17 and 32

1/f = (17 + 32) / 544

1/f = 49/544

Taking the reciprocal

f = 544/49

f = 11.1 cm

Therefore, Focal length of the lens is 11.1cm