Photoelectric Effect
Tut 1 - Basics
1. What is meant by the photoelectric effect?
This is the process whereby electrons are ejected from a metal surface when light of suitable frequency is incident on that surface.
2. What is meant by threshhold frequency?
This is the minimum frequency of light needed to emit electrons from a certain metal surface.
3. In what units is Work Function measured?
joules J
4. What is meant by Work Function?
This is the minimum energy that an electron in the metal needs to be emitted from the metal surface.
5. What is the significance of the photoelectric effect?
The photoelectric effect
- confirms that light has a particle nature
- establishes the quantum theory (light energy is quantized)
6. What does the term "quanta" mean?
The term "quanta" is plural for "quantum".
- Energy exists in packages (energy unit called quantum)
- Radiated energy is quantized
- i.e. energy exists in multiples of a smallest possible value
7. What is meant by the term "photon?
- quanta of electromagnetic radiation
- the actual incoming light
8. What are photoelectrons?
These are the electrons that are ejected by the light. They are ordinary electrons.
9. Is the photoelectric effect more pronounced at higher or lower frequencies of light?
higher frequencies
At higher frequencies they have greater energy.
10. What is meant by the phrase "the dual nature of light"?
light can behave both as a particle or as a wave.