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प्रश्न
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.
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उत्तर
(i) Number of photons per unit per second in both the beams is same as they have the same intensity.
(ii) The maximum kinetic energy of photoelectrons is given by
E=hν−ϕw
hereh=Planck's constant
ν=Frequency of incident light
ϕ=Workfunction of the material
We know that the frequency of blue beam is more than that of red beam. So, from the equation of maximum kinetic energy, we can say that the maximum kinetic energy of the photoelectrons of the blue beam will be more
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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 (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.
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]
If the total energy of radiation of frequency 1014 Hz is 6.63 J, calculate the number of photons in the radiation. (Planck’s constant = 6.63 x 10–34 J.s.)
A beam of monochromatic radiation is incident on a photosensitive surface. Answer the following question giving reason :
Do the emitted photoelectrons have the same kinetic energy?
What is photoelectri effect ? Defin (i) Stopping potential (ii) Photoelectric work function.
State how will you use this graph to detennine the value of Planck's constant.
Who discovered the phenomenon of photoelectric emission?
