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. This is also known as a good conductor
- The resistance R of a conductor is defined as the ratio of the potential difference V across to the current I in it
Resistance of a component is the ratio of the potential difference and current
- Resistance is measured in Ohms (Ω)
- An Ohm is defined as one volt per ampere
- The resistance controls the size of the current in a circuit
- A higher resistance means a smaller current
- A lower resistance means a larger current
- All electrical components, including wires, have some value of resistance