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A biconvex lens of focal length f forms ...

A biconvex lens of focal length f forms a circular image of radius r of sun is focal plane. Then, which option is correct?

A

`pir^2 prop f`

B

`pir^2propf^2`

C

If lower half part is covered by black sheet, then area of the image is equal to `(pir^2)/2`

D

If f is doubled, intensity will increase

Text Solution

Verified by Experts

The correct Answer is:
B
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