What must be the distance between an object and a converging lens of focal length 20cm to produce an erect image two times the object height?
A
20cm
B
15cm
C
10cm
D
5cm
Verified Correct Answer: C.
Physical Principles & Numerical Solution
F = \(\frac{uv}{u + v}\); v = 2u
20 = \(\frac{ux - 2u}{u + (-2u)}\); u = 10cm
Source: Myschool Past Questions Archive (Record #28259)