An electronic device in which the flow of electrons is through a vacuum is known as vacuum tube.
A vacuum tube usually contains a cathode which is the electron emitter, an anode (plate) which is the electron collector and one or more electrodes (grids) for controlling the flow of electrons between cathode and anode. These electrodes are housed in a highly evacuated glass envelope. The ability of vacuum tubes to conduct current in vaccum enables them to perform different functions.
A vacuum tube usually contains a cathode which is the electron emitter, an anode (plate) which is the electron collector and one or more electrodes (grids) for controlling the flow of electrons between cathode and anode. These electrodes are housed in a highly evacuated glass envelope. The ability of vacuum tubes to conduct current in vaccum enables them to perform different functions.
