1are the plates long enough ?
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
-
UP 0 DOWN 0 0 3
3 Answers
1max 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
