This document describes an experiment to determine Planck's constant using the photoelectric effect. The apparatus includes a power supply, variable battery, photocell, light source, filters of different colors, voltmeter, and ammeter. When light of sufficient frequency strikes the photocell, electrons are emitted. By measuring the stopping potential at which the photocurrent becomes zero for different frequencies, Planck's constant can be calculated from Einstein's photoelectric equation. The results show that the photoelectric effect depends on light frequency but not intensity.

1. MY NAME IS
AMEER HAMZA
ROLL NO 3
ASLAM-U-ALIKUM
RESPECTIVE MA’AM
AND STUDENTS

2. DETERMINETHE
PLANKS CONSTANT
USING
PHOTOELECTRIC EFFECT

3. PHOTOELECTRIC
EFFECT

4. APPRATUS:
■ Power supply
■ Variable battery
■ Photocell
■ Light source
■ Filters of different colors
■ Volt meter
■ ammeter

5. PHOTOELECTRIC EFFECT
 Conversion of light energy into the electrical energy under some
specific conditions is called photo electric effect.
 The device which convert the light energy in to the electrical
energy is called photocell
 The minimum frequency of incident light which can cause
photoelectric emission is called threshold frequency

6. EINSTINE PHOTO ELECTRICAL
EQUATION
p
h
o
t
o
n
nucleus
 Minimum energy required to eject the electron from the metal surface is called
work function
 𝐸 𝑝 = 𝜙0 + 𝑘 ⋅ 𝐸max
 ℎ𝑣 = ℎ𝑣0 + 𝑘 ⋅ 𝐸max
E=ℎ𝑣

7. METAL
electron
CURRENT
ELECTRONIC CURRENT

8. +- - +

9. source
Filter
Light
Anode
Cathode
Photo cell
Voltmeter
Ammeter
Variable battery
+- - +

10. source
Filter
Light
Anode
Cathode
Photo cell

11. Anode
Cathode
Photo cell
𝑒−1

12. source
Filter
Light
Anode
Cathode
Photo cell
Voltmeter
Ammeter
Variable battery
+- - +
𝑒−1
A B
I

13. source
Filter
Light
Anode
Cathode
Photo cell
Voltmeter
Ammeter
Variable battery
+- - +
𝑒−1
A
B

14. source
Filter
Light
Anode
Cathode
Photo cell
Voltmeter
Ammeter
Variable battery
+- - +
𝑒−1
A
B

15. ■ The potential difference at which photo current equal to zero is called stopping
potential
■ It is denoted by 𝑉0
■ The product of stopping potential ad charge on electron is called K.E max
■ Kemal = e 𝑉0

16. EXPERIMENTAL RESULTS
INTENSITYVARIATION
■ Photoelectric effect does not
depend upon the intensity of light
FREQUENCYVARIATION
■ Photoelectric effect depend upon
the frequency of light

17. THANKYOU