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The exposure time of a camera lens at t...

The exposure time of a camera lens at the `(f)/(2.8)` setting is `(1)/(200) ` second. The correct time of exposure at `(f)/(5.6)` is

A

0.04 s

B

0.20 s

C

0.40 s

D

0.02 s

Text Solution

Verified by Experts

The correct Answer is:
D
` t prop ` ( f - number ) ` ""^2 prop ( 1) /(("Aperture")^ 2 ) `
`(t_ 2 ) /( 1//200) = ((f//2.8)/(f//5.6))^ 2 `
`t _ 2 = 4xx ( 1 ) /(200) = ( 1 ) /(50) = 0.02 ` sec.
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