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The focal length of a glass lens in air ...

The focal length of a glass lens in air is f. When immersed in water (refractive index `mu`) its focal length would be

A

f

B

`ltf`

C

`gtf`

D

nothing can be decided

Text Solution

Verified by Experts

The correct Answer is:
C
It must be remembered that the focal length of a lens submerged in water becomes four times its focal length in air.
`f_(omega)=4f_(a)`
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