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A photocell is placed at 1 m distance fr...

A photocell is placed at 1 m distance from light source when distance is changed to `(1)/(2)`m no.of photoelectron emitted from cathode will come

A

decrease by a factor of `4`

B

increase by a factor of `4`

C

decrease by a factor of `2`

D

increase by a factor of `2`

Text Solution

Verified by Experts

The correct Answer is:
B
Photocurrent `prop` Intensity
Intensity due to point source at r m is `I prop 1/r^(2)`
As distance is reduced to half, the photocurrent due to point source will increase by a factor of 4.
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ALLEN -SIMPLE HARMONIC MOTION-Exercise-04 [B]
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