The word "potential" refers to stored energy per unit charge at a given point in a circuit — just like gravitational potential energy is the stored energy per unit mass at a given height.
At the positive terminal of a battery, charges are at high potential (lots of energy). As they flow around the circuit through resistors and lamps, they lose energy — their potential drops. At the negative terminal, they are at low potential (little energy remaining).
The potential difference across a component is simply the difference in potential energy per coulomb between the two ends. A large p.d. means each coulomb transfers lots of energy — that component does more work (like a brighter bulb or a faster motor).
The battery's job is to restore the potential — like the ski lift returning skiers to the top of the hill so they can descend (do work) again.
Quick Check: A battery transfers 60 J of energy to 5 C of charge. What is the potential difference of the battery?
V = E / Q = 60 ÷ 5 = 12 V.
This how it works covers How It Works: What "Potential" Actually Means within Potential Difference for GCSE Physics. Revise Potential Difference in Electricity for GCSE Physics with 14 exam-style questions and 30 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 6 of 14 in this topic. Use this how it works to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Potential Difference
Which of the following is the correct definition of potential difference?
Explain what is meant by a potential difference of 6 V across a component.