photoelectric effect

metallic plates P(collector) & Q(emitter) are separated by a distance of 0.10m. These r connected through an ammeter without any cell. a magnetic field B exists parallel to the plates. light of wavelengths between 400nm & 60nm falls on the emitter whose work function is 2.39eV. Calculate minimum value of B
such that no current is recorded in the ammeter

3 Answers

1
ankit mahapatra ·

around 6.77*10-13 T ?

1
Philip Calvert ·

are the plates long enough ?

1
Philip Calvert ·

max KE of photoelectron = hν - φ

= 4.125E-15 *3E8/.6E-7 - 2.39 eV

= 4.125x5 - 2.39 eV

=20.625 - 2.39 eV

we can find velocity and hence knowing the radius of cirlce it will move in , the B required

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