An object is placed in front of a converging lens of a fo...
An object is placed in front of a converging lens of a focal length 20cm. The image is virtual and has a magnification of 2. What is the distance of the object from the lens?
5cm
10cm
30cm
40cm
Correct answer is B
V = -2u
F = uvu+v
20 = uv−2uu−2u
u = 10cm