2. We know that the light has dual nature.
The Phenomena of interference & diffraction etc. can be
explained on the basis of wave theory of light.
Whereas the phenomena of Photoelectric Effect , compton
effect can be explained on the basis of particle theory of light.
3. The ejection of electrons from a metallic surface
when the light of suitable frequency is allowed to fall
on the surface.
4. This suitable frequency is called Threshold
Frequency and the corresponding
wavelength is called threshold wavelength.
Work function: The work function is the
energy required to remove an electron from
the highest filled level in the Fermi
distribution of a solid.
5.
6. •Incident light triggers the emission of (photo)electrons
from the cathode.
•Some of them travel toward the collector (anode) with an
initial kinetic energy.
•The applied voltage V either accelerates (if positive) or
decelerates (if negative) the incoming electrons.
•The intensity I of the current measured by the ammeter as
a function of the applied voltage V is a measurement of the
photoelectron properties, and therefore a measurement of
the properties of the photoelectric effect.
7. Think about hitting a ball into outer space.
If you don't hit it hard enough, it will just come back
down. No matter how many times you hit it.
If superman hit it, he could get it into space.
Similarly, no matter how many photons strike the metal, if
none of them has sufficient energy to eject an electron
from a metal atom, you won't get a current.
If the energy the taken up by the electron is sufficient to
allow it to be released from the metal atom, you will get a
current.
9. V
V :- potential difference
Vs :- stopping potential
ʋ :- frequency (constant)
10. Vs1 Vs2 Vs3
Ʋ1
Ʋ2
Ʋ3
The stopping potential depends on the frequency:-Higher
frequencies generates higher energy electrons.
Ʋ1 > Ʋ2 > Ʋ3
11. Photoelectric effect is directly proportional to intensity.
If the frequency of the incident light is less than the threshold
frequency then no electron ejected, no matter what the
intensity.
The maximum kinetic energy of the electrons depend on the
frequency of the incident light.
The electrons were emitted immediately - no time lag.
