Dual Nature Flashcards
What is work function?
The minimum amount of energy required by an electron to escape from metal surface is called the work function of the metal. It is generally measured in electron volt (eV).
What is thermionic emission?
The process of emission of electrons by heating the metal.
What is Field Emission?
The process of emission of electrons by applying a strong electric field across the metal surface is called field emission.
What is Photoelectric Emission?
The process of emission of electrons when a light of suitable frequency is incident on the metal surface is called photoelectric emission.
What is photoelectric effect?
The phenomenon of emission of electrons from a metal surface when a light of suitable frequency is incident on it is called photoelectric effect.
Define threshold frequency
The frequency of incident radiation below which no photo electrons are emitted from the metal surface is called threshold frequency.
Define threshold wavelength
The wavelength corresponding to threshold frequency is called threshold wavelength.
What is saturation current?
Saturation current is the maximum value of photo electric current which corresponds to the case when all the photoelectrons emitted by the emitter plate reach the collector plate.
What is stopping potential?
The minimum value of retarding potential at which the photo electric current becomes zero is called stopping potential.
What are de-Broglie waves?
According to de-Broglie, all the moving particles are associated with waves. Such waves are called de-Broglie waves or matter waves
What are de-Broglie wavelength?
The wavelength of the matter wave is called de-Broglie wavelentgh.
State Heisenberg’s Uncertainty Principle.
According to this principle, it is not possible to measure both the position and the momentum of an electron or any other particle at the same time exactly.
What is a photo-cell?
A device which converts light energy into electrical energy is called a photo-cell. It works on the principle of photo-electric current.
