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A lens having focal length f and apertur...

A lens having focal length `f` and aperture of diameter `d` forms an image of intensity `I`. Aperture of diameter `d//2` in central region of lens is covered by a black paper. Focal length of lens and intensity of image now will be respectively

A

`f and l/4`

B

`(3f)/4and (l)/(2)`

C

`fand (3l)/4`

D

`f/2andl/2`

Text Solution

Verified by Experts

The correct Answer is:
C
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