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प्रश्न
Define (i) stopping potential and (ii) threshold frequency, using Einstein’s equation and drawing necessary plot between relevant quantities.
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उत्तर
Stopping potential: For a particular frequency of incident radiation, the minimum negative (retarding) potential V0 for which the photocurrent stops or becomes zero is called the cut-off or stopping potential.
Threshold frequency: The minimum frequency required for photoelectrons to be emitted from a metal surface is called the threshold frequency.
The graph between stopping potential and frequency of incident radiation is shown below:
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संबंधित प्रश्न
The threshold wavelength of silver is 3800Å. Calculate the maximum kinetic energy in eV of photoelectrons emitted, when ultraviolet light of wavelength 2600Å falls on it.
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Write Einstein's photoelectric equation and mention which important features in photoelectric effect can be explained with the help of this equation.
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Write its S.I. unit of (intensity of radiation)
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Dimensions of ‘resistance’ are same as (where h is Planck's constant and e is charge):
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(ii) Find the angle of incidence at face AB so that the emergent ray grazes along the face AC.
- Calculate the frequency of a photon of energy 6.5 × 10−19 J.
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The graphs below show the variation of the stopping potential VS with the frequency (ν) of the incident radiations for two different photosensitive materials M1 and M2.
Express work function for M1 and M2 in terms of Planck’s constant(h) and Threshold frequency and charge of the electron (e).
If the values of stopping potential for M1 and M2 are V1 and V2 respectively then show that the slope of the lines equals to `(V_1-V_2)/(V_(01)-V_(02))` for a frequency,
ν > ν02 and also ν > ν01
