To measure the potential difference across a component, a voltmeter must be placed in parallel with that component in order to measure the difference in energy from one side of the component to the other. Potential difference is also known as voltage and is measured in volts (V).
When a charge moves through a potential difference, electrical work is done and energy transferred. The potential difference can be calculated using the equation:
potential difference = current × resistance
This is when:
One volt is the potential difference when one joule of work is done moving one coulomb of charge.
What is the potential difference if a current of 2 A flows through a resistance of 40 Ω?
= 2 × 40
= 80 V
What is the resistance of a component if 12 V causes a current of 2 A through it?
= 6 Ω