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Question
Define the term "Threshold frequency", in the context of photoelectric emission.
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Solution
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.
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Answer the following question.
Define the term "Threshold frequency", in the context of photoelectric emission.
Define the work function of a metal. Give its unit.
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 ______.
Give an example each of a metal from which photoelectric emission takes place when irradiated by
- UV light
- visible light.
Name the factors on which photoelectric emission from a surface depends.
