Question

A convex lens of power +2.5 D is in contact with
a concave lens of focal length 25 cm. The power
of combination is
254
(1) -1.5 D
(2) OD
25
IZSTOO
(3) +1.5 D
2.slo
644
(4) +6.5 D​

Answer 1

Answer:

option A

Explanation:

for convex lens:-

P1 = + 2.5D

for concave lens:-

focal length= 25 cm

P2 = 1/f(in m)

= 1/-0.25

= -4D

•power of combination = P1 + P2

= +2.5 + (-4)

= -1.5D