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Figure 3 shows some of the apparatus that students use to determine the resistance of a piece of iron wire - Edexcel - GCSE Physics - Question 2 - 2023 - Paper 2
Question 2
Figure 3 shows some of the apparatus that students use to determine the resistance of a piece of iron wire. Add connecting wires, a voltmeter and an ammeter to comp... show full transcript
Worked Solution & Example Answer:Figure 3 shows some of the apparatus that students use to determine the resistance of a piece of iron wire - Edexcel - GCSE Physics - Question 2 - 2023 - Paper 2
Step 1
Add connecting wires, a voltmeter and an ammeter
Answer
To complete the circuit in Figure 3:
- Connect a voltmeter in parallel with the iron wire to measure the voltage across it. This is essential for determining the potential difference.
- Connect an ammeter in series with the iron wire, ensuring that it measures the current flowing through the wire.
- Use connecting wires to link the voltmeter, ammeter, variable resistor, and battery, forming a complete circuit. The configuration should ensure no contradictory symbols are used.
Step 2
Figure 4 shows a graph of the results.
Answer
In response to the graph, the straight line should show the relationship between resistance (in ohms) and length (in cm). The line will likely pass through the origin and demonstrate that as the length of the wire increases, the resistance also increases.
Step 3
Step 4
Explain the effect of the resistor on current.
Answer
- A variable resistor increases the resistance in the circuit, which subsequently limits the flow of current.
- As the resistance increases, the current remains constant, preventing excessive heat generation within the iron wire.
- Therefore, this regulation is crucial for maintaining safe operational conditions, reducing the risk of damage from overheating.