Advertisements
Advertisements
प्रश्न
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`
Advertisements
उत्तर
1) From the graph,
Threshold frequency = `10 xx 10^14 Hz`
`v_0 = 10^15 Hz`
2) The work function of the metal
`w = hv_0`
`= 6.63 xx 10^(-34) xx 15^15`
`= (6.63 xx 10^(-19))/(1.6 xx 10^(-19))`
= 4.14 eV
3) `E_k = 8 eV`
Stopping potential = `K.E._"max" - phi`
`=> 8 - 4.14 = 3.86 eV`
`V = 3.86/e xx ev = 3.86 V`
APPEARS IN
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.
Draw a plot showing the variation of photoelectric current versus the intensity of incident radiation on a given photosensitive surface.
The work functions for potassium and caesium are 2.25 eV and 2.14 eV respectively. Is the photoelectric effect possible for either of them if the incident wavelength is 5180 Å?
[Given : Planck’s constant = 6.63 x 10–34 J.s.;
Velocity of light = 3 x 108 m/s; 1 eV = 1.6 x 10–19 J]
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?
A beam of monochromatic radiation is incident on a photosensitive surface. Answer the following question giving reason :
Does the kinetic energy of the emitted electrons depend on the intensity of incident radiation?
In photoelectric effect, why should the photoelectric current increase as the intensity of monochromatic radiation incident on a photosensitive surface is increased? Explain.
With reference to the photoelectric effect, what is meant by threshold wavelength?
Two metals A and B have work functions 4 eV and 6 eV respectively. Which metal has a lower threshold wavelength for photoelectric effect?
Photoelectric effect is possible ______.
