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प्रश्न
Would you prefer a material with a high melting point or a low melting point to be used as a cathode in a diode?
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उत्तर
We will prefer a material with high melting point to be used as the cathode in a diode. The material of the cathode of a diode should be resistant to high temperature, have high melting point and be electrically conductive because thermionic emission occurs at high temperature.
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संबंधित प्रश्न
The work function of caesium metal is 2.14 eV. When light of frequency 6 × 1014 Hz is incident on the metal surface, photoemission of electrons occurs. What is the
- maximum kinetic energy of the emitted electrons,
- Stopping potential, and
- maximum speed of the emitted photoelectrons?
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Would you prefer a material with a high work-function or a low work-function to be used as a cathode in a diode?
An isolated metal sphere is heated to a high temperature. Will it become positively charged due to thermionic emission?
Define the term "Threshold frequency", in the context of photoelectric emission.
If a light of wavelength 330 nm is incident on a metal with work function 3.55 eV, the electrons are emitted. Then the wavelength of the wave associated with the emitted electron is (Take h = 6.6 × 10–34 Js)
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Name the factors on which photoelectric emission from a surface depends.
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- the energy of the incident radiation,
- the maximum kinetic energy of the emitted electron and
- the stopping potential of the surface.
What is responsible for electrical conduction in metals?
In the boundary-wall analogy, what is the minimum push needed for a free electron to jump over the wall and come out?
What is the work function (\[\phi_0\]) of a metal?
What must supplied energy enable a metal electron to overcome for electron emission to occur?
In the mechanism of electron emission, what happens after surface positive ions hold free electrons inside the metal?
Which is an example of thermionic emission?
Which is an example associated with photoelectric emission?
