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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
Draw a neat labelled circuit diagram of experimental arrangement for study of photoelectric effect.
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 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.
The graph shows the variation of stopping potential with frequency of incident radiation for two photosensitive metals A and B. Which one of the two has higher value of work-function? Justify your answer.
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 :
On what factors does the number of emitted photoelectrons depend?
Who discovered the phenomenon of photoelectric emission?
In Hertz’s experimental investigation, how were electromagnetic waves produced?
What happened to high-voltage sparks across the detector loop when the emitter plate was illuminated with ultraviolet light from an arc lamp?
