Advertisements
Advertisements
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.
Advertisements
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
APPEARS IN
संबंधित प्रश्न
The photoelectric current in a photoelectric cell can be reduced to zero by a stopping potential of 1.8 volt. Monochromatic light of wavelength 2200Å is incident on the cathode. Find the maximum kinetic energy of the photoelectrons in joules. [Charge on electron = 1.6 x 10-19 C]
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 (i) the intensity of light is gradually 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.
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.
Use Einstein's photoelectric equation to explain the observations from this graph ?
Plot a labelled graph of IVsl where Vs is stopping potential versus frequency f of the incident radiation.
State how will you use this graph to detennine the value of Planck's constant.
Photoelectric effect is possible ______.
Consider an electron in front of metallic surface at a distance d (treated as an infinite plane surface). Assume the force of attraction by the plate is given as `1/4 q^2/(4πε_0d^2)`. Calculate work in taking the charge to an infinite distance from the plate. Taking d = 0.1 nm, find the work done in electron volts. [Such a force law is not valid for d < 0.1nm].
