Series & Parallel Circuits

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FreeScienceLessons · AQA PhysicsCurrent in Series Circuits

FreeScienceLessons · AQA PhysicsCurrent in Parallel Circuits

Cognito · AQA Physics · 2026/27 examsSeries & Parallel Circuits — Recent overview

Key equations & rules

V = IR

Potential difference = current × resistance

Given in exam

P = IV

Power = current × potential difference

Given in exam

Series circuits — three rules — fill in the table

Property	Rule (series)
Current
Potential difference
Total resistance
Adding a resistor
If one component fails

Parallel circuits — three rules — fill in the table

Property	Rule (parallel)
Potential difference
Current
Total resistance
Adding a branch
If one branch fails

Ammeter & voltmeter placement — always asked — fill in the table

Component	Placement	Why
Ammeter
Voltmeter

Exam questions — 7 questions · 12 marks total

1 markSeries rulesAQA 8463 style

In a series circuit, two resistors of 4Ω and 6Ω are connected to a 12V battery. What is the current through the circuit?

A 2 A

B 1.2 A

C 0.5 A

D 3 A

1 markParallel rulesAQA Jun 2022 P1 style

In a parallel circuit, what is true about the potential difference across each branch?

A It is the same throughout the whole circuit

B It is shared between each branch

C It is the same across each branch

D It increases with each additional branch

2 marksV = IR calculationAQA Jun 2023 P1 style

A resistor has a resistance of 15Ω. A current of 0.4A flows through it. Calculate the potential difference across the resistor. Give the unit. (2 marks)

+20 XP

1 markAmmeter placementAQA Jun 2023 P1 Q6.1

A student sets up a circuit to measure the resistance of a filament lamp. How should the ammeter be connected?

A In series with the filament lamp

B In parallel with the filament lamp

C In parallel with the battery

D Between the ammeter and the voltmeter

2 marksParallel currentAQA Nov 2021 P1 style

In a parallel circuit, the total current from the battery is 0.6A. One branch carries 0.2A. What is the current in the other branch? Explain your reasoning. (2 marks)

+20 XP

1 markEffect of adding componentsAQA Jun 2022 P1 Q11 style

A parallel circuit has two branches. A third branch (resistor) is added. What happens to the total resistance of the circuit?

A It increases

B It stays the same

C It decreases

D It depends on the value of the resistor added

4 marksSeries circuit — full calculationAQA 8463 style

A series circuit contains a battery of 9V and two resistors. Resistor 1 has resistance 12Ω. The current in the circuit is 0.3A.
(a) Calculate the total resistance of the circuit. (1 mark)
(b) Calculate the resistance of Resistor 2. (1 mark)
(c) Calculate the potential difference across Resistor 1. (1 mark)
(d) State the potential difference across Resistor 2. (1 mark)

+40 XP

Quick recall flashcards

Series & Parallel Circuits

Series circuits — three rules — fill in the table

Parallel circuits — three rules — fill in the table

Ammeter & voltmeter placement — always asked — fill in the table

Module complete! 🎉