A student wants to find the resistance of a length of wire.
The student connects the wire in a series circuit with a battery, a switch, an ammeter and a variable resistor. The student also uses a voltmeter.
The Table shows the student's results.
Table
| Potential difference in V\text{V}V | Current in A\text{A}A |
|---|---|
| 1.0 | 0.25 |
| 2.0 | 0.50 |
| 3.0 | 0.68 |
| 4.0 | 1.00 |
Describe how the ammeter and the voltmeter should be connected in the circuit.
Explain why the student includes a variable resistor in the circuit.
Identify the anomalous result in the Table.
Calculate the resistance of the wire.
Use a result that is not anomalous.
The student opens the switch between readings.
Explain why.
81 exam-style questions on Edexcel GCSE Physics 10.2 Resistance, covering 10.2.1 Current in a circuit and conservation at junctions, 10.2.2 Resistance and variable resistors, 10.2.3 Series and parallel resistance, 10.2.4 I–V characteristics of components, and 10.2.5 LDRs and thermistors. Each one has a worked solution and a mark scheme showing where the marks go.