Advertisements
Advertisements
प्रश्न
Define the term "Threshold frequency", in the context of photoelectric emission.
Advertisements
उत्तर
For a given Photosensitive material, there is a certain minimum cut off frequency at which Photoelectric emission is possible is called Threshold frequency, i.e. At this frequency just emission of photoelectrons happens without giving them any kind of additional energy. Higher the work function of the material, greater is the Threshold frequency. See the figure below of two different metals having different Threshold Frequency.
APPEARS IN
संबंधित 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?
An isolated metal sphere is heated to a high temperature. Will it become positively charged due to thermionic emission?
A diode value is connected to a battery and a load resistance. The filament is heated, so that a constant current is obtained in the circuit. As the cathode continuously emits electrons, does it become more and more positively charged?
The wavelength λe of an electron and λp of a photon of same energy E are related by ______.
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
Why do metals have a large number of free electrons?
What do you mean by electron emission? Explain briefly various methods of electron emission.
In which case is electron emission from a metal not known?
Consider Figure for photoemission.
How would you reconcile with momentum conservation? Note light (photons) have momentum in a different direction than the emitted electrons.
Give an example each of a metal from which photoelectric emission takes place when irradiated by
- UV light
- visible light.
