Calculate the focal length of a convex lens which produces a virtual image at a distance of 50 cm of an object placed 20 cm in front of it.
Answers:
V = – 50 cm (Virtual image)
u = -20 cm
1/v – 1/u = 1/f
1/-50 – 1/-20 = 1/f
(-2 + 5)/100 = 1/f
3/100 = 1/f
F = 33.3 cm