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In a photoelectric effect set up, a poin...

In a photoelectric effect set up, a point source of light of power `3.2 xx10^(-3) W` emits monoenergetic photons of energy `5eV`.The source is located at a distance of a stationary metallic sphere of work function `3eV` and radius `8xx10^(-3)m`.The efficiency of photoelectron emission is one for every `10^(6)` incident photons.Assume that the sphere is isolated and initially neutral and the photoelectrons are initially swept away after emission.
Find the number of photons emitted per second

A

`10^(5)`

B

`2xx10^(15)`

C

`4xx10^(15)`

D

`6xx10^(15)`

Text Solution

Verified by Experts

The correct Answer is:
C
Energy of emitted photons `E_(1)=5eV=5xx1.6xx10^(-19) J`
Power of point source =`3.2xx10^(-3) J//s`
Energy emitted per second =`(n)=E_(2)/E_(1)=4xx10^(15)` photons
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