A student connects a resistor to a battery. Explain what is meant by the terms 'current' and 'potential difference' in this circuit, and describe how increasing the resistance of the resistor affects the current when the potential difference stays the same.

Eduqas GCSE Physics — 7.1 Current, potential difference and resistance · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

Current is the rate of flow of charge through the circuit.
Potential difference (voltage) is the energy transferred per unit charge, the driving force that pushes charge around the circuit.
Increasing the resistance decreases the current.
Because resistance opposes the flow of charge, so with the same potential difference fewer charges flow per second.

Examiner tips

  • Define current and potential difference using exam‑style terminology.
  • Explain the effect of resistance on current using the relationship I=V/R.
  • Show the reasoning that resistance limits charge flow.
  • Use concise, correct units and terms.

Mark scheme (4 marks)

  1. Current is the rate of flow of charge (through the circuit)
  2. Potential difference (voltage) is the energy transferred per unit charge / the driving force that pushes charge around the circuit
  3. Increasing resistance decreases the current
  4. Because resistance opposes / limits the flow of charge (and with the same potential difference, less charge flows per second)

Key terms in this question

current · potential difference · resistance

Related

More Current, potential difference and resistance questions

▶ Try answering this question with AI marking (free) →