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प्रश्न
Use Einstein's photoelectric equation to explain the observations from this graph ?
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उत्तर
The Einstein's photoelectric equation is \[K_{max} = \frac{1}{2}m \nu^2_{max} = h\nu - \phi_o\]
From the graph, we noticed that
(i) The value of stopping potential is different for radiation of different frequencies.
\[\text { As } \]
\[e V_o = h\nu - \phi_o \]
\[\text { Hence }, V_o \propto \nu\]
(ii) The value of stopping potential is more negative for radiation of higher incident frequency.
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संबंधित प्रश्न
Sketch the graphs showing variation of stopping potential with frequency of incident radiations for two photosensitive materials A and B having threshold frequencies vA > vB.
(i) In which case is the stopping potential more and why?
(ii) Does the slope of the graph depend on the nature of the material used? Explain.
Light of intensity ‘I’ and frequency ‘v’ is incident on a photosensitive surface and causes photoelectric emission. What will be the effect on anode current when (i) the intensity of light is gradually increased. In each case, all other factors remain the same. Explain, giving justification in each case.
Light of intensity ‘I’ and frequency ‘v’ is incident on a photosensitive surface and causes photoelectric emission. What will be the effect on anode current when (ii) the frequency of incident radiation is increased. In each case, all other factors remain the same. Explain, giving justification in each case.
Light of intensity ‘I’ and frequency ‘v’ is incident on a photosensitive surface and causes photoelectric emission. What will be the effect on anode current when the anode potential is increased? In each case, all other factors remain the same. Explain, giving justification in each case.
Two monochromatic beams, one red and the other blue, have the same intensity. In which case (i) the number of photons per unit area per second is larger, (ii) the maximum kinetic energy of the photoelectrons is more? Justify your answer.
Draw a plot showing the variation of photoelectric current versus the intensity of incident radiation on a given photosensitive surface.
The work functions for potassium and caesium are 2.25 eV and 2.14 eV respectively. Is the photoelectric effect possible for either of them if the incident wavelength is 5180 Å?
[Given : Planck’s constant = 6.63 x 10–34 J.s.;
Velocity of light = 3 x 108 m/s; 1 eV = 1.6 x 10–19 J]
A beam of monochromatic radiation is incident on a photosensitive surface. Answer the following question giving reason :
Does the kinetic energy of the emitted electrons depend on the intensity of incident radiation?
In photoelectric effect, why should the photoelectric current increase as the intensity of monochromatic radiation incident on a photosensitive surface is increased? Explain.
Light of wavelength 4000 Å is incident on two metals A and B. Which metal will emit photoelectrons, if their work functions are 3.8 e V and 1.6 e V respectively?
