Question

Consider a beam of electrons (each electron with energy E₀) incident on a metal surface kept in an evacuated chamber. Then ______.

Options

• no electrons will be emitted as only photons can emit electrons.

• electrons can be emitted but all with an energy, E₀.

• electrons can be emitted with any energy, with a maximum of E₀ – φ (φ is the work function).

• electrons can be emitted with any energy, with a maximum of E₀.

Answer 1

Consider a beam of electrons (each electron with energy E₀) incident on a metal surface kept in an evacuated chamber. Then electrons can be emitted with any energy, with a maximum of E₀.

Explanation:

If a beam of electrons of having energy E₀ is incident on a metal surface kept in an evacuated chamber.

The electrons can be emitted with maximum energy E₀ (due to elastic collision) and With any energy less than E₀, when part of the incident energy of electron is used in liberating the electrons from the surface of metal.