AQA A-Level Physics Paper 1, June 2022: Question 14
1 mark · Easy difficulty · Multiple Choice
Identify the physical quantity represented by eVs in photoelectric emission, given Vs is the stopping potential.
Practise this questionQuestion
Question text
14 In photoelectricity, Vs is the stopping potential.
What quantity is eVs?
[1 mark]
A energy of an incident photon
B maximum kinetic energy of a photoelectron
C threshold frequency × the Planck constant
D work function
Mark scheme
Show the mark scheme
14 B (AO2) maximum kinetic energy of a photoelectron
How to answer it
Stopping Potential and Kinetic Energy in the Photoelectric Effect
What this question tests
This question tests your understanding of the definitions and key equations associated with the photoelectric effect, specifically how the stopping potential ( Vs ) relates to the maximum kinetic energy of photoelectrons.
Exam Question Breakdown
✅ Correct Answer
Option B: maximum kinetic energy of a photoelectron
💡 Key Knowledge
- Stopping Potential ( Vs ): The minimum potential difference required to stop the fastest moving photoelectrons from reaching the anode.
- Energy Conservation: When a photoelectron is stopped, all its maximum kinetic energy is converted into electrical potential energy ( E = QV = e Vs ).
🧠 Exam Technique
In multiple-choice questions involving definitions, link the symbols immediately. Recognize that e is the elementary charge (charge of an electron) and Vs is the stopping potential. The product of charge and potential difference ( Q×V ) always yields energy in joules or electronvolts.
❌ Common Errors
- Confusing stopping potential energy ( e Vs ) with the work function ( Φ ), which is the minimum energy required to liberate an electron from the metal surface (Option D).
- Confusing it with the total energy of the incident photon ( hf , Option A).
Topics
Physics · 3.2 Particles and radiation
Question and mark scheme from the AQA A-Level Physics examination, Paper 1, June 2022. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.