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What is the term used for emission of electrons from metals by bombarding the metal surface with electrons?

What is the term used for emission of electrons from metals by bombarding the metal surface with electrons? Correct Answer <span style="">Secondary emission</span>

Concept:

  • The liberation of electrons from the surface of a metal is known as Electron Emission.
  • The minimum energy required by an electron to just escape (i.e. with zero velocity) from metal's surface is called Work function (W0) of the metal.
  • There are basically four methods of producing electron emission,
  1. Thermionic Emission: In this type, the metal is heated to a sufficient temperature to enable the free electrons to come out of its surface.
  2. Field Emission: In this type, a very strong electric field is applied to the metal which pulls the electrons out of the surface due to the attraction of the positive field.
  3. Photoelectric Emission: In this type, the light of a certain frequency is made to fall on the metal surface which leads to the emission of electrons.
  4. Secondary Emission: In this type, electrons emit from the surface by bombardment of high speed electron.

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