The
photoelectric effect is the process of emission or ejection of
electrons or free carriers from the surface of a metallic object in
response to the incident light when hits the surface of the metallic
object. Electrons emitted in such manner are called Photoelectrons.
In this process, the electrons within a metallic object absorb energy
from the photons and acquired more energy than the work function of
the object to get itself ejected off from the surface of the object..
it is found that energies of the emitted electrons to be independent
of the intensity of the incident radiation. But it is depended on the
frequency of the light beam incident on the metallic surface.
For
a given metal surface, there exists a certain minimum frequency of
incident radiation below which no photoelectrons get emitted and that
frequency is known as the threshold frequency. As increasing the
frequency by keeping the number of incident photons fixed, it
increase the maximum kinetic energy of the photoelectrons emitted.
Above the threshold frequency, the maximum kinetic energy of the
emitted photoelectrons depend on the frequency of the incident light,
but independent of the intensity of the incident light. But for a
given material and frequency of the incident radiation, the rate at
which photoelectrons are ejected is directly proportional to the
intensity of the incident light.
The
time lag between the incidence of the radiation and the emission of
the photoelectrons is very small, less than 10-9
second. The direction of the distribution of the emitted
electrons peaks in the direction of polarization of the incident
light, if it is linearly polarized.
Comments
Post a Comment