Defining resistance
- Resistance is defined as the opposition to current
- For a given potential difference: the higher the resistance, the lower the current
- Wires are often made from copper because copper has a low electrical resistance
- Materials with low electrical resistance are good conductors
- The resistance of a conductor is calculated using the following equation, sometimes referred to as Ohm's law:
- Where:
- = resistance, measured in Ω
- = potential difference, measured in V
- = current, measured in A
- One ohm is equivalent to one volt per ampere
- The resistance in a circuit determines the amount of charge that can flow (current)
- A higher resistance means a smaller current
- A lower resistance means a larger current
- All electrical components, including wires, have some value of resistance