Explain 'stopping potential' and 'threshold frequency' in photoelectric emission.Give an appropriate graph.

Define threshold frequency for photoelectric emission.

Define stopping potential and threshold frequency in relation to photoelectric effect.

Write Einstein's photoelectrical equation in terms of the stopping potential and the threshold frequency for a given photosensitive material. Draw a plot showing the variation of stopping potential vs the frequency of incident radiation.

Is photoelectric emission possible at all frequencies?

Photoelectric effect When light of sufficiently small wavelength is incident on a metal cathode, it may emit electsons called photoelectrons. This is called photoelectric effect. Above threshold frequency, the stopping potential and hence the energy of the photoelectrons is directly proportional to the frequency. Slope of graph is given by

Photoelectric effect When light of sufficiently small wavelength is incident on a metal cathode, it may emit electsons called photoelectrons. This is called photoelectric effect. Above threshold frequency, the stopping potential and hence the energy of the photoelectrons is directly proportional to the frequency. In the given figure, we see the variation of stopping potential with the frquency of incident radiation for three metals A, B and C Which metal has the largest threshold wavelength?

Photoelectric effect When light of sufficiently small wavelength is incident on a metal cathode, it may emit electsons called photoelectrons. This is called photoelectric effect. Above threshold frequency, the stopping potential and hence the energy of the photoelectrons is directly proportional to the frequency. In the given figure, we see the variation of stopping potential with the frquency of incident radiation for three metals A, B and C Which of these metals A, B or C are suitable for photoelectric cell?