question_answer

Consider a beam of electrons (each electron with energy \[{{\operatorname{E}}_{0}}\]) incident on a metal surface kept in an evacuated chamber. Then,

A) no electrons will be emitted as only photons can emit electrons.

B) electrons can be emitted but all with an energy, \[{{\operatorname{E}}_{0}}\].

C) electrons can be emitted with any energy, with a maximum of \[{{\operatorname{E}}_{0}}\] - \[\phi \](\[\phi \] is the work function).

D) electron can be omitted with energy, with a maximum of \[{{\operatorname{E}}_{0}}\].

Correct Answer: D

Solution :

Option [d] is correct.

Explanation: If a beam of electrons of having energy \[{{\operatorname{E}}_{0}}\] is incident on a metal surface kept in an evacuated chamber.

The electrons can be emitted with maximum energy \[{{\operatorname{E}}_{0}}\] (due to elastic collision) and with any energy less than \[{{\operatorname{E}}_{0}}\], when part of incident energy of electron is used in liberating the electrons from the surface of metal.