Summary
The potential difference is the energy transferred per unit charge flowing from one point to another in a circuit, measured in volts (V). Example: A battery creates a potential difference across a circuit, allowing current to flow.
- Work Done — Potential difference can also be defined as the work done per unit charge, expressed as V = W / Q. Example: If 10 joules of work is done to move 2 coulombs of charge, the potential difference is 5 volts.
- Electrical Power — Power is the rate of doing work or energy transfer, calculated as P = IV, where I is the current and V is the potential difference. Example: If a device uses 2 amperes of current at a potential difference of 5 volts, the power is 10 watts.
Exam Tips
Key Definitions to Remember
- Potential difference is the energy transferred per unit charge.
- Power is the rate of doing work or energy transfer.
Common Confusions
- Confusing potential difference with current.
- Misunderstanding the relationship between power, voltage, and current.
Typical Exam Questions
- What is potential difference? It is the energy transferred per unit charge in a circuit.
- How do you calculate electrical power? Power is calculated as P = IV, where I is current and V is potential difference.
- What is the formula for potential difference in terms of work done? V = W / Q, where W is work done and Q is charge.
What Examiners Usually Test
- Understanding of potential difference and its measurement.
- Ability to calculate power using different formulas.
- Application of formulas to solve circuit problems.