PHYSICS CONNECTION
Build a resistor network from Ohm’s law
Series and parallel resistance rules follow from current and voltage relationships. Redrawing a network by its junctions can make the real arrangement clear.
Series: R = ΣR Parallel: 1/R = Σ(1/R)
Follow the reasoning
- Identify which components share the same two junctions.
- Reduce one series or parallel group at a time.
- Use V = IR to recover the individual currents or voltages.
OFFICIAL OCR QUESTIONS
Try it in a past paper 2
Open the question, then use its mark scheme to check your work.
Question 3
Calculate resistance in a series-and-parallel network.
Question 6
Read a lamp characteristic and use circuit measurements to find internal resistance.
A curated collection checked against the question papers and mark schemes; not a complete past-paper catalogue. Links open official OCR PDFs in a new tab.
ORIGINAL PHYSICSUK QUESTIONS
Put the ideas to work
More practice is on its way
No PhysicsUK question linked yet. New eligible questions appear here as the bank grows.
Specification outcomes (5)
- 4.2.3(a) Define resistance using R = V / I and state the unit ohm.
- 4.2.3(b) State and apply Ohm’s law.
- 4.3.1(c) Calculate total resistance of resistors in series using R = R₁ + R₂ + …
- 4.3.1(d) Calculate total resistance of resistors in parallel using 1/R = 1/R₁ + 1/R₂ + …
- 4.3.1(e) Analyse circuits with components including both series and parallel arrangements.