Photo electric effect and compton effect

1. THE PHOTOELECTRIC EFFECT AND
THE COMPTON EFFECT
Prepared by
P. KRITIKA
18R21A12B0

2. The photoelectric effect
 The ejection of electrons from a metallic surface when the
light of suitable wavelength is incident on the surface is
known as photoelectric effect and the emitted electron is
known as photoelectron

3. The construction for photoelectric
experiment
• In this experiment the electron
plates are photosensitive metal
surfaces enclosed in the
evacuated quartz tube.
• One of the plate is connected to
the ammeter and positive
terminal of battery and other
plate is connected to the negative
terminal of the battery and
galvanometer.

4. • PHOTOELECTRIC EFFECT - WORKING
 When a beam of light falls on photosensitive metal plate c
which is called emitter .As shown in the above figure.
 The plate c emits photoelectrons due to photoelectric effect
The photo electrons emitted by the plate c will be attracted
towards the positive plateA. these electrons flows in the
circuit causing a deflection in the galvanometer.
 Such current is known as photoelectric current .

5. • When a beam of radiations allowed to incident on one
plate the current starts to flow in the circuit due to which
the galvanometer shows deflection
The flow of current ensures the fact that when radiations
of suitable wavelength are incident on a photosensitive
metal surface electrons are ejected
The no.of electrons ejected and their kinetic energy
depends on the following factors
1.The potential difference between the plates
2.Intensity of incident radiation
3.The frequency of incident radiation
4. Photo sensitive metal

6. The applications of Photoelectric effect
The photoelectric effect
 It is used in burglar alarm
 It is most commonly used
in solar panels
 It is used in cameras for
exposure meter

7. The compton effect
• The Compton effect(also called compton
scattering ) is the result of high-energy photon
colliding with a electron , which releases
loosely bound electrons from the other shell of
the atom or molecule
• The scattered radiation experienced a
wavelength shift that cannot be explained in
terms of classical wave theory , thus lending to
support einstein’s photon theory .

8. The applications of Compton effect
• The compton scattering is a prime importance to
radiobiology,as it happened to be nost probable
interaction of high energy X-rays with atomic nuclei in
living being and is applied in radiation therapy .
• In material physics ,compton scattering can be used to
probe the wave function of the electrons in matter in the
momentum representation .

9. Einstein’s photoelectric equation
ℎ𝜐 = ℎ𝜐 𝜊 +
1
2
𝑚𝑣2
1
2
𝑚𝑣2
= ℎ 𝑣 − 𝜐 𝜊
Compton shift expression
Δ𝜆 = 𝜆𝜄_
𝜆 =
ℎ
𝑚 𝜊
1−cos 𝜃
𝑐

11. Thank You