The process of electron emission from a metal surface by supplying thermal energy to it is known as thermionic emission.
In this method, the metal is heated to sufficient temperature (about 2500 deg c) to enable the free electrons to leave the metal surface. The number of electrons emitted depends upon the temperature. The higher the temperature, the greater is the emission of electrons. this type of emission is employed in vacuum tubes.
In this method, the metal is heated to sufficient temperature (about 2500 deg c) to enable the free electrons to leave the metal surface. The number of electrons emitted depends upon the temperature. The higher the temperature, the greater is the emission of electrons. this type of emission is employed in vacuum tubes.
