When stopping potential is applied in an experiment on photoelectric effect, no photocurrent is observed. This means that
When stopping potential is applied in an experiment on photoelectric effect, no photocurrent is observed. This means that
The correct option is B The photoelectrons are emitted but are re-absorbed by the emitter metal
See the electrons on being hit by a photon receive its energy. If that energy is greater than the work function then the electron will come out or else no chance.
Even though it is not very clear that it will come out, it might face resistance on the way from other free electrons.
Few lucky ones will come out without encountering any collisions on the way. These will have the maximum kinetic energy
Emax = hν – Φ
Others who spent some energy in collisions will come out with lesser energy than this. Now if I make the other plate negative , then it will start repelling the photo electrons. The ones with lesser energy will return back to emitter plate, the one with more energy will still manage to reach the collector plate
If I decrease the potential further even the fastest moving electron will slow down and be stopped before it hits the collector. So the potential at which even the fastest electron just misses the collector plate and turns back is called the stopping potential.
So yeah, even at stopping potential the photo electrons are emitted but are reabsorbed by the emitter plate.
The photoelectrons are emitted but are re-absorbed by the emitter metal
See the electrons on being hit by a photon receive its energy. If that energy is greater than the work function then the electron will come out or else no chance.
Even though it is not very clear that it will come out, it might face resistance on the way from other free electrons.
Few lucky ones will come out without encountering any collisions on the way. These will have the maximum kinetic energy
Emax = hν – Φ
Others who spent some energy in collisions will come out with lesser energy than this. Now if I make the other plate negative , then it will start repelling the photo electrons. The ones with lesser energy will return back to emitter plate, the one with more energy will still manage to reach the collector plate
If I decrease the potential further even the fastest moving electron will slow down and be stopped before it hits the collector. So the potential at which even the fastest electron just misses the collector plate and turns back is called the stopping potential.
So yeah, even at stopping potential the photo electrons are emitted but are reabsorbed by the emitter plate.
