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प्रश्न
It is observed in an experiment on the photoelectric effect that an increase in the intensity of the incident radiation does not change the maximum kinetic energy of the electrons. Where does the extra energy of the incident radiation go? Is it lost? State your answer with explanatory reasoning.
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उत्तर
Electrons are emitted when electromagnetic radiation with a frequency greater than the threshold frequency is incident on a metal surface. It has been noticed that not every incident photon is capable of realising an electron. In fact, the number of electrons emitted per second is far less than the number of photons incident per second. Photons that are ineffective in the liberation of electrons are reflected (or scattered) or absorbed, causing the temperature of the metal surface to rise. The maximum kinetic energy of a photoelectron is determined by the frequency of incident radiation and the metal's threshold frequency. It has nothing to do with the intensity of the incident radiation. As the intensity increases, so does the number of electrons emitted per second.
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संबंधित प्रश्न
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The following graphs show the variation of stopping potential corresponding to the frequency of incident radiation (ν) for a given metal. The correct variation is shown in graph [ν0 = threshold frequency].
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(B) |
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(C) |
(D) |
Draw a neat labelled diagram of photo-current as a function of accelerating potential for fixed incident intensity but different incident frequencies for the same emitter material.
