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The anode voltage of a photocell is kept...

The anode voltage of a photocell is kept fixed. The wavelength `lamda` of the light falling on the cathode is gradually changed. The plate current I of the photocell varies as follows:

A

B

C

D

Text Solution

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The correct Answer is:
B
With the increase in wavelength energy of the photon decreases. Therefore the KE of the electron coming out from the cathode also decreases. Due to which there will be a small decrease in plate current and once `lambda` becomes more than threshold wavelength electron will not come out from the cathode and hence current will become zero.
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