Question

Consider a beam of electrons (each electron with energy `E_(0))` incident on a metal surface kept in an evacuated chamber. Then
A. no electrons will be emitted only photons can emit electrons
B. electrons can be emitted but all with an energy, `E_(o)`
C. electrons can be emitted with any energy, with a maximum of `E_(o)-phi` (`phi` is the work function)
D. electrons can be emitted with any energy, with a maximum of `E_(o)`

Answer 1

When a bean of electrons of energy `E_(o)` is incident on a metal surface kept in an evaacuated chamber electrons can be emitted with maximum energy `E_(o)` (due to elastic collidion) and with any energy less then `E_(o),` when part of incident energy of electron is used in liberating the electrons from the surface of metal.