This common misconceptions covers Common Misconceptions within Potential Difference for GCSE Physics. Revise Potential Difference in Electricity for GCSE Physics with 14 exam-style questions and 30 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 9 of 14 in this topic. Use this common misconceptions to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 9 of 14
Practice
14 questions
Recall
30 flashcards
⚠️ Common Misconceptions
Misconception 1: "Voltage is the same as current"
Voltage (potential difference) and current are completely different quantities. Current is the rate of flow of charge (A); voltage is the energy per unit charge (V). They are related by Ohm's Law (V = IR), but they measure different things. High voltage does not mean high current — that depends on resistance too.
Misconception 2: "Voltage is used up as current flows"
Voltage is not "used up" — it is the energy transferred per coulomb. What happens in a circuit is that the voltage "drops" across components as energy is transferred to them. The sum of voltage drops equals the supply voltage (Kirchhoff's Voltage Law). The charges themselves are not consumed.
Misconception 3: "A voltmeter must be in series to measure voltage"
This is the opposite of the truth. A voltmeter must always be connected in parallel across the component you're measuring. Connecting it in series would drastically change the circuit (a voltmeter has very high resistance), and you'd simply measure the supply voltage, not the component voltage.