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
Correct Answer: Option C
Explanation
F = (frac{uv}{u + v}); v = 2u
20 = (frac{ux – 2u}{u + (-2u)}); u = 10cm