Advertisements
Advertisements
प्रश्न
Define the work function of a metal. Give its unit.
Advertisements
उत्तर
The minimum energy needed for an electron to escape from the metal surface is called the work function of that metal. Its unit is electron volt (eV).
APPEARS IN
संबंधित प्रश्न
Find the maximum frequency of X-rays produced by 30 kV electrons.
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?
Would you prefer a material with a high melting point or a low melting point 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?
The anode of a thermionic diode is connected to the negative terminal of a battery and the cathode to its positive terminal.
The wave associated with a moving particle of mass 3 × 10–6 g has the same wavelength as an electron moving with a velocity 6 × 106 ms–1. The velocity of the particle is
What do you mean by electron emission? Explain briefly various methods of electron emission.
Photoelectric emission is observed from a metallic surface for frequencies ν1 and ν2 of the incident light (ν1 > ν2). If the maximum value of kinetic energy of the photoelectrons emitted in the two cases are in the ration 1 : n then the threshold frequency of the metallic surface is ______.
Name the factors on which photoelectric emission from a surface depends.
The work function of a metal is 2.31 eV. Photoelectric emission occurs when the light of frequency 6.4 × 1014 Hz is incident on the metal surface. Calculate
- the energy of the incident radiation,
- the maximum kinetic energy of the emitted electron and
- the stopping potential of the surface.
