What is Resistance?
- Resistance is the opposition to current
- For a given potential difference:
The higher the resistance, the lower the current
- Potential difference, current and resistance are related by the following equation:
Use the formula triangle to help you rearrange the equation
- The unit of resistance is the ohm (Ω)
Determining Resistance
- To find the resistance of a component, set up a circuit like the one shown below
A circuit to determine the resistance of a component
- The power supply should be set to a low EMF (voltage) to avoid heating the component – 1 or 2 volts is typically enough
- Measurements of the potential difference and current should then be taken from the voltmeter and ammeter respectively
- Finally, these readings should be substituted into the following equation: