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The focal length of a thin lens in vacuu...

The focal length of a thin lens in vacuum is `f`. If the material of the lens has `mu = 3//2`, its focal length when immersed in water of refractive index `4//3` will be.

A

f

B

`(4f)/(3)`

C

2 f

D

4 f

Text Solution

Verified by Experts

The correct Answer is:
D
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Knowledge Check

  • 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

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    A
    `f_(1) = (f)/(2)`
    B
    `f_(2) = -2f`
    C
    `f_(2) = -(3f)/(2)`
    D
    Data is insufficient

  • The focal length of a convex lens of glass of refractive index 1.5 is 2 cm. The focal length of the lens when immersed in a liquid of refractive index 1.25 will be:

    A
    2.5 cm
    B
    5 cm
    C
    1 cm
    D
    4 cm

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    A convex lens of refractive index 1.5 has a focal length of 18 cm in air. Calculate the change in its focal length when it is immersed in water of refractive index (4)/(3) .

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