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Two plano-concave lenses (1 and 2) of gl...

Two plano-concave lenses (1 and 2) of glass of refractive index 1.5 have radii of curvature 20 cm and 10 cm. They are placed in contact with their curved surface towards each other and the space between them is filled with liquid of refractive index 4/3. Then the combination is

A

concex lens of focallenght 40 cm

B

concave lens of focal length 40 cm

C

concave lens of focal lenghts `66.6` cm

D

convex lens of focal lentght 66.6 cm

Text Solution

Verified by Experts

The correct Answer is:
B
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