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S2 Science: Electric Circuits, Current, Voltage and Resistance (Paper 1: basics)
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S2 Science: Electric Circuits, Current, Voltage and Resistance (Paper 1: basics)
The three commonest errors are assuming series current falls along the circuit, adding parallel voltages, and simply adding parallel resistances. Label the series and parallel parts on the diagram first.
Direct answers Answers in order: ampere, volt, same at every point, 2 A, 12 ohms, 15 V, 10 ohms, 1 A, about 0.667 ohms, no.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 |
| Suggested time | 20 |
| Difficulty mix | Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1 |
| Chapter | Chapter: S2 Science: Electric Circuits, Current, Voltage and Resistance |
| Level | S2 Science |
02 Questions (10 items)
- FoundationWhat is the unit of electric current?
- FoundationWhat is the unit of voltage?
- FoundationIn a series circuit, how does the current compare at different points?
- IntermediateA 12 ohm resistor is connected to a 24 V supply. What current flows?
- IntermediateA bulb has 6 V across it and 0.5 A through it. What is its resistance?
- IntermediateA wire of resistance 5 ohms carries 3 A. What is the voltage across it?
- ChallengeA 4 ohm and a 6 ohm resistor are joined in series. What is the total resistance?
- ChallengeA 12 V battery is in series with 3 ohm and 9 ohm resistors. What is the current?
- ChallengeThree 2 ohm resistors are connected in parallel. What is the total resistance, to three decimal places?
- Error redoA student says each resistor in a series circuit has the full supply voltage across it. Is that right?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | The ampere (A) | Current is measured in amperes and given the symbol I. |
| 2 | The volt (V) | Voltage is energy per unit charge, measured in volts. |
| 3 | It is the same at every point | Series has only one path, so charge cannot pile up or vanish. |
| 4 | 2 A | Using V = IR, twenty-four divided by twelve is two. |
| 5 | 12 ohms | R is V divided by I, so six divided by 0.5 is twelve. |
| 6 | 15 V | V equals IR, five times three is fifteen. |
| 7 | 10 ohms | Series resistances add, four plus six is ten. |
| 8 | 1 A | Total resistance is twelve, and twelve divided by twelve is one. |
| 9 | About 0.667 ohms | One over three halves is two thirds, about 0.667 ohms. |
| 10 | No | The voltages across series resistors add up to the supply voltage and are shared in proportion to resistance. |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
Start with the units and one rule: a series loop has a single path, so the current never changes. For numbers, list V, I and R and solve for the missing one.Tutor Registration →
Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.