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Potential difference

The flowing through a component depends on:

  • the of the
  • the across the component

Measuring potential difference

Potential difference is also known as and is measured in volts (V). The potential difference across a component is measured using a placed with the component.

Circuit with a cell, switch and lamp. A voltmeter is connected in parallel with the lamp.

Energy, potential difference and charge

When a charge moves through a potential difference, is done by the power supply and energy is transferred from it to the component and/or its surroundings. The potential difference can be calculated using the equation:

\(potential~difference = \frac{work~done}{charge}\)

This is when:

  • potential difference is measured in volts (V)
  • work done is measured in joules (J)
  • charge is measured in coulombs (C)

Example

2 C of charge transfers 4 J of energy. Calculate the potential difference needed.

\(potential~difference = \frac{energy~transferred}{charge}\)

\(potential~difference = \frac{4}{2}\)

\(= 2~V\)

Question

3 C of charge moves through a potential difference of 6 V. Calculate the energy transferred.