what is the mechanism in discharge tube
Answers
Answer:
The fundamental mechanism is the Townsend discharge, which is the sustained multiplication of electron flow by ion impact when a critical value of electric field strength for the density of the gas is reached.
Answer:
A tube used to study the electrical conduction through gases at low pressure known as discharge tube. ... The discharge tube in connected with a vacuum pump to reduce the pressure inside the tube is gradually reduced, using a pump the following phenomenon are observed as explained below.
The fundamental mechanism is the Townsend discharge, which is the sustained multiplication of electron flow by ion impact when a critical value of electric field strength for the density of the gas is reached.
A gas- discharge tube is usually a glass tube with two electrodes sealed through its walls. When a voltage is applied to the two electrodes and the pressure of the gas in the tube is reduced, eventually a pressure is reached at which a current flows, and the gas begins to glow.
hydrogen gas
For better results in a cathode tube experiment, an evacuated (low pressure) tube is filled with hydrogen gas that is the lightest gas (maybe the lightest element) on ionization, giving the maximum charge value to the mass ratio (e / m ratio = 1.76 x 10 ^ 11 coulombs per kg).
You need the low pressure in the tube so that the passage of the beam of electrons is not impeded very much by collision with air molecules. You need a reasonably high accelerating voltage to give the electrons enough kinetic energy to make the fluorescent screen glow when the electrons hit the screen.
In order to return to the ground state, electrons release excess energy in the form of light. The light is differently colored in each tube because of the different wavelengths of light that must be released in each instance.
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8. Oxygen - Blue-violet
9. Water Vapor - Pink
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