IIT JEE , AIEEE Forum - Physics , Modern Physics

rakhiagrawal

1.when a monochromatic point soutce of light is at a distance of 0.2 m from a photoelectric cell,the cut-off voltage & the saturation current are respectively 0.6 volt & 18.0 mA.if the same source is placed 0.6m away from the photoelectric cell ,then the

1.stopping potential will be 0.2 volt

2.stopping potential will be 0.6 volt

3.saturation current will be 6.0 mA

4.saturation current will be 0.02 mA

jain108

( 2)

jain108

intensity hence current

1/distance^2

current will be 2 mA

frequency ramains same so stopping potential will be the same

hence ans 2

madman

(2) is correct as stopping potential depends only on frequency of light while only intensity of light changes with distance

skmishra

its a good question. With the change of distance the energy of photons does not change. so stopping potential will not change. Regarding intensity of light it varies inversly to square of distance and current is directly peoportional to intensity

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