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प्रश्न
How can they be made to leave the metal surface? (State any two ways)
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उत्तर
Electron emission from the metal surface can be (any two):
1) Thermionic emission – when energy is supplied as heat
2) Photoelectric emission – when energy is supplied as energy.
3) Field emission – when energy is supplied by applying an electric field to accelerate the electrons.
4) Secondary emission – when energy is supplied from the kinetic energy of other electrons on collisions with them.
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संबंधित प्रश्न
Answer the following questions based on a hot cathode ray tube
Name the charged particles
Answer the following questions based on a hot cathode ray tube.
State the approximate voltage used to heat the filament
In a cathode ray tube, what is the function of anode?
State the penetrating range of α, β and γ radiations.
State two properties that a substance should possess when used as a thermionic emitter.
How is a zinc sulphide screen affected when a cathode ray beam strikes it?
In a cathode ray tube state the purpose of covering cathode by thorium and carbon.
What do you understand by the term radioactivity?
A radioctive sample decays `7/8` times its original quantity in 15 minutes. The half-life of the sample is ______.
Assertion (A): The force of repulsion between atomic nucleus and α-particle varies with distance according to inverse square law.
Reason (R): Rutherford did α-particles scattering experiment.
