Two lenses of focal lengths 24 cm and – 36 cm are held in contact. The image of an object at infinity will be formed by the combination at;
Answer & explanation
Correct answer: option 2
1/f = 1/f1 + 1/f2
f1 = 24cm f2 = -36cm
1/f = (1/24)-(1/36) = (3-2)/72 = 1/72
f = 72
(1/v)- (1/∞) Hence v=f=72cm