What it looks like: Components on separate branches — current has MULTIPLE paths to choose from.
Current rule:
- Current SPLITS at junctions
- Itotal = I₁ + I₂ + I₃
- More current flows through lower resistance branches
- Think: water splitting into multiple pipes
Voltage rule:
- Voltage is the SAME across each branch
- V₁ = V₂ = V₃ = Vsupply
- Each branch connects directly to the supply
Resistance rule:
- Total resistance is LESS than the smallest individual resistance
- 1/Rtotal = 1/R₁ + 1/R₂ + 1/R₃
- Adding more branches DECREASES total resistance (more paths = easier flow)
Key consequence: If one branch breaks, the others KEEP WORKING — that's why houses use parallel circuits!
This deep dive covers Parallel Circuits — Multiple Paths within Series & Parallel Circuits for GCSE Physics. Revise Series & Parallel Circuits in Electricity for GCSE Physics with 20 exam-style questions and 30 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 4 of 16 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Series & Parallel Circuits
In a series circuit, what is true about the current at all points?
A student adds an extra lamp to a parallel circuit. Explain how this affects the total current from the supply and the brightness of the original lamps.