Defining Potential Difference
- A cell makes one end of the circuit positive and the other negative. This sets up a potential difference (d) across the circuit
- The potential difference across a component in a circuit is defined as the energy transferred per unit charge flowing from one point to another
- The energy transfer is from electrical energy into other forms
- Potential difference is measured in volts (V). This is the same as a Joule per coulomb (J C-1)
- If a bulb has a voltage of 3 V, every coulomb of charge passing through the bulb will lose 3 J of energy
- The potential difference of a power supply connected in series is always shared between all the components in the circuit
The potential difference is the voltage across each component in a circuit
- Potential difference or voltage is measured using a voltmeter
- A voltmeter is always set up in parallel to the component you are measuring the voltage for
Potential difference can be measured by connecting a voltmeter in parallel between two points in a circuit