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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
Write three characteristic features in photoelectric effect that cannot be explained on the basis of wave theory of light, but can be explained only using Einstein's equation.
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.
In an experiment of the photoelectric effect, the graph of maximum kinetic energy EK of the emitted photoelectrons versus the frequency v of the incident light is a straight line AB shown in Figure 6 below:
Find:
1) Threshold frequency of the metal
2) The work function of the metal.
3) Stopping potential for the photoelectrons emitted by the light of frequency `v = 30 xx 10^14 Hz`
A photosensitive surface emits photoelectrons when red light falls on it. Will the surface emit photoelectrons when blue light is incident on it? Give reason.
What change will you observe if intensity of incident radiation is changed but the frequency remains the same?
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.
What facilitated the escape of free, charged particles from the metal surface?
Where are the electrons that absorb energy from incident radiation located?
What must electrons near the metal surface overcome before they can escape?
