Advertisements
Advertisements
प्रश्न
How would the stopping potential for a given photosensitive surface change if the intensity of incident radiation was decreased? Justify your answer.
Advertisements
उत्तर
A decrease in incident radiation intensity would have no effect on the stopping potential of a certain photosensitive surface. This is because the stopping potential is exclusively determined by frequency rather than intensity of incident radiation. The kinetic energy of photoelectrons is determined only by the frequency of incident radiation, but the number of photoelectrons emitted from the surface is inversely proportional to the intensity of the received light. As a result, decreasing the intensity of the incident radiation would result in fewer photons being produced, but it would have no influence on their kinetic energy or stopping potential.
APPEARS IN
संबंधित प्रश्न
Monochromatic radiation of wavelength 640.2 nm (1 nm = 10−9 m) from a neon lamp irradiates photosensitive material made of caesium on tungsten. The stopping voltage is measured to be 0.54 V. The source is replaced by an iron source and its 427.2 nm line irradiates the same photo-cell. Predict the new stopping voltage.
Is it always true that for two sources of equal intensity, the number of photons emitted in a given time are equal?
Can a photon be deflected by an electric field? Or by a magnetic field?
The threshold wavelength of a metal is λ0. Light of wavelength slightly less than λ0 is incident on an insulated plate made of this metal. It is found that photoelectrons are emitted for some time and after that the emission stops. Explain.
Planck's constant has the same dimensions as
The equation E = pc is valid
If the frequency of light in a photoelectric experiment is doubled, the stopping potential will ______.
The collector plate in an experiment on photoelectric effect is kept vertically above the emitter plate. A light source is put on and a saturation photocurrent is recorded. An electric field is switched on that has a vertically downward direction.
When a metal plate is exposed to a monochromatic beam of light of wavelength 400 nm, a negative potential of 1.1 V is needed to stop the photo current. Find the threshold wavelength for the metal.
(Use h = 6.63 × 10-34J-s = 4.14 × 10-15 eV-s, c = 3 × 108 m/s and me = 9.1 × 10-31kg)
Explain how does (i) photoelectric current and (ii) kinetic energy of the photoelectrons emitted in a photocell vary if the frequency of incident radiation is doubled, but keeping the intensity same?
Show the graphical variation in the above two cases.
