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प्रश्न
With reference to the photoelectric effect, what is meant by threshold wavelength?
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उत्तर
The threshold wavelength is the maximum wavelength of light corresponding to which the photoelectric effect just starts.
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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.
The photoelectric work function for a metal is 4.2 eV. If the stopping potential is 3V, find the threshold wavelength and maximum kinetic energy of emitted electrons.
(Velocity of light in air = 3 x 108m/s,
Planck's constant = 6·63 x10-34 J -s,
Charg.e ori electron = 1·6 x 10 -19 C)
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.
Draw a plot showing the variation of photoelectric current with collector potential for different frequencies but same intensity of incident radiation ?
Use Einstein's photoelectric equation to explain the observations from this graph ?
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.
Two metals A and B have work functions 4 eV and 6 eV respectively. Which metal has a lower threshold wavelength for photoelectric effect?
In what year was the phenomenon of photoelectric emission discovered?
What must electrons near the metal surface overcome before they can escape?
