Answers

2016-02-02T18:56:06+05:30
P1=3D and P2=-5D
Power of the combination = 3D+(-5D)
                                           =-2D
since P=1/f
-2D=1/f
f=1/-2m
f=-0.5m
f=-50cm
Therefore the combination will act like a concave lens of focal length 50 cm
u=-50cm
v=?
1/f=1/v-1/u
1/v=1/f+1/u
1/v=1/-50+1/-50
1/v=1/-25
v=-25cm
therefore avirtual image will be formed at  a distance of 25
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