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A plano convex lens is made of material ...

A plano convex lens is made of material having refractive index 1.5. The radius of curvature of curved surface is 60 cm. The focal length of the lens is……….. cm.

A

`-60`

B

120

C

60

D

`-120`

Text Solution

Verified by Experts

The correct Answer is:
B

`(1)/(f)= (n-1)((1)/(R_(f))-(1)/(R_(2)))`
`implies (1)/(f)= 0.5((1)/(60))= (1)/(120)`
`f= 120`
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