๐ฏ Common Question Types:
- Calculate total resistance in series (2 marks)
- Calculate total resistance in parallel (3 marks)
- State current or voltage at a point in the circuit (1 mark)
- Explain why houses use parallel circuits (2 marks)
- Mixed circuit calculation with multiple steps (4โ6 marks)
๐ Key Command Words:
- Identify โ state which type of circuit it is
- Calculate โ show all steps, state units (ฮฉ)
- Explain โ use current, voltage, resistance rules
- State โ brief answer, no working needed
โ ๏ธ Common Mistakes to Avoid:
- Adding parallel resistances directly โ use 1/R formula
- Getting a parallel answer bigger than the smallest R โ impossible
- Saying current is "shared equally" in parallel โ it splits by resistance
- Forgetting that parallel branches all have the same voltage
- In mixed circuits, solve parallel group first, then add series resistors
Quick Check: Three resistors of 2ฮฉ, 3ฮฉ and 5ฮฉ are connected in series. What is the total resistance?
Rtotal = Rโ + Rโ + Rโ = 2 + 3 + 5 = 10 ฮฉ.
Quick Check: Two 8ฮฉ resistors are connected in parallel. What is their combined resistance?
Using the product-over-sum shortcut: R = (8 ร 8) รท (8 + 8) = 64 รท 16 = 4 ฮฉ. (Or: two equal resistors in parallel = half the individual value.)
This exam tips covers Exam Tips for Series and Parallel Circuits 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 15 of 16 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
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.