A diverging lens of focal length 30cm produces an image 20cm from the lens. Determine the object distance

A. 10cm
B. 12cm
C. 50cm
D. 60cm

Correct Answer: Option B

B. 12cm

Explanation

1/u+1/v=1/f

1/u=1/f+1/v

= 1/30+1/20=2+3/6

u = 60/5=12cm