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Question
What is the photoelectric effect? Define stopping potential and photoelectric work function.
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Solution
- The phenomenon of emission of electrons from a metal surface, when radiation of appropriate frequency is incident on it, is known as the photoelectric effect.
- If increasingly negative potentials were applied to the collector in the experiment of the photoelectric effect, the photocurrent decreases and for some typical value (– V0), photocurrent becomes zero. This value of V0 is termed as cut-off or stopping potential.
- The minimum amount of energy required to be provided to an electron to pull it out of the metal from the surface is called the work function of the metal.
RELATED QUESTIONS
Choose the correct option.
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v = 5v0?
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(h = Planck's constant, c =velocity of light)
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The stopping potential in the context of photoelectric effect depends on the following property of incident electromagnetic radiation ______.
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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) |
Photoelectric emission is observed from a metallic surface for frequencies ν1 and ν2 of the incident light rays (ν1 > ν2). If the ratio of the maximum value of the kinetic energy of the photoelectrons emitted in the first case to that in the second case is 2 : K, then the threshold frequency of the metallic surface is ______.
Give Einstein's explanation of the photoelectric effect.
