UK Domestic Supply

The UK domestic supply provides electricity as an alternating current (a.c.).

For the Edexcel exam, you must recall two specific values for the UK mains supply:

Electric current can be delivered to a circuit in two ways:

Alternating current (a.c.): An electric current that continuously and regularly changes its direction as it moves around a circuit.
Direct current (d.c.): An electric current that flows in one direction only. This is the type of current provided by cells and batteries.

Get full access to revision notes, key terms, and exam tips for every subtopic.

Common Mistake
Students frequently mix up the specific values for mains electricity. Memorise that $50$ is the Frequency (in $\text{Hz}$ ) and $230$ is the Potential Difference (in $\text{V}$ ).
2
When asked to define alternating current in an exam, ensure you state that the current changes direction 'continuously' or 'regularly' to secure the mark.
3
If a calculation question in another part of the exam involves an appliance plugged into the mains but does not state a voltage, examiners expect you to recall and use the figure of $230\text{ V}$ .
4
Edexcel mark schemes strongly prefer the term 'potential difference' over 'voltage', so always use 'potential difference' in your written answers.

Alternating current (a.c.): An electric current that continuously and regularly changes its direction, moving back and forth around a circuit.
Direct current (d.c.): An electric current that flows in one direction only, from the positive terminal toward the negative terminal.
Frequency: The number of complete cycles of alternating current per second, measured in Hertz (Hz).
Potential difference: The work done or energy transferred per unit charge between two points in a circuit.

Put your knowledge into practice — try past paper questions for Physics

Alternating current (a.c.): An electric current that continuously and regularly changes its direction, moving back and forth around a circuit.
Direct current (d.c.): An electric current that flows in one direction only, from the positive terminal toward the negative terminal.
Frequency: The number of complete cycles of alternating current per second, measured in Hertz (Hz).
Potential difference: The work done or energy transferred per unit charge between two points in a circuit.

The UK domestic supply provides electricity as an alternating current (a.c.).

For the Edexcel exam, you must recall two specific values for the UK mains supply:

Electric current can be delivered to a circuit in two ways:

Alternating current (a.c.): An electric current that continuously and regularly changes its direction as it moves around a circuit.
Direct current (d.c.): An electric current that flows in one direction only. This is the type of current provided by cells and batteries.

Get full access to revision notes, key terms, and exam tips for every subtopic.

Common Mistake
Students frequently mix up the specific values for mains electricity. Memorise that $50$ is the Frequency (in $\text{Hz}$ ) and $230$ is the Potential Difference (in $\text{V}$ ).
2
When asked to define alternating current in an exam, ensure you state that the current changes direction 'continuously' or 'regularly' to secure the mark.
3
If a calculation question in another part of the exam involves an appliance plugged into the mains but does not state a voltage, examiners expect you to recall and use the figure of $230\text{ V}$ .
4
Edexcel mark schemes strongly prefer the term 'potential difference' over 'voltage', so always use 'potential difference' in your written answers.

Alternating current (a.c.): An electric current that continuously and regularly changes its direction, moving back and forth around a circuit.
Direct current (d.c.): An electric current that flows in one direction only, from the positive terminal toward the negative terminal.
Frequency: The number of complete cycles of alternating current per second, measured in Hertz (Hz).
Potential difference: The work done or energy transferred per unit charge between two points in a circuit.

Put your knowledge into practice — try past paper questions for Physics

Alternating current (a.c.): An electric current that continuously and regularly changes its direction, moving back and forth around a circuit.
Direct current (d.c.): An electric current that flows in one direction only, from the positive terminal toward the negative terminal.
Frequency: The number of complete cycles of alternating current per second, measured in Hertz (Hz).
Potential difference: The work done or energy transferred per unit charge between two points in a circuit.