Question

a convex lens of focal length 25cm and a concave lens of focal length 10cm are placed in close contact with one another (a)what is the power of this combination?
(b) what is the focal length of this combination ?
(c) is this combination converging or diverging

Answer 1

for convex lens focal length is positive and for concave it is negative....concave lens is diverging lens

Answer 2

Answer:- (a) -6 D

(b) - 16.66 cm

(c) Diverging lens.