Voltage
Learning Objectives
- Students will be able to define voltage as potential difference
- Students will be able to measure voltage using a voltmeter
- Students will be able to understand electromotive force (EMF)
Core Concepts
- Potential difference
- Electromotive force
- Voltage in circuits
Formulas
$$V = \frac{W}{q}$$
Voltage as work done per unit charge
$$V = \varepsilon - Ir$$
Terminal voltage with internal resistance, where ε is EMF and r is internal resistance
Units
| Volt | V |
Interesting Fact
Voltage is measured between two points, so you cannot have voltage 'at' a single point
Key Scientist
Alessandro Volta
Defined electric potential and gave his name to the unit of voltage
Philosophy
Voltage as potential difference exemplifies relational properties in physics — nothing has inherent voltage, only relative electrical potential with respect to other points.
Want to truly master this? Try the interactive lesson!
Start Lesson