In the circuit below, the voltmeter reading is zero - AQA - A-Level Physics - Question 27 - 2020 - Paper 1
Question 27
In the circuit below, the voltmeter reading is zero.
When the temperature of the thermistor T is increased, the voltmeter reading changes.
Which change to the circ... show full transcript
Worked Solution & Example Answer:In the circuit below, the voltmeter reading is zero - AQA - A-Level Physics - Question 27 - 2020 - Paper 1
Step 1
A reduction in the emf of the cell
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Answer
Reducing the emf of the cell will lower the voltage across the components, potentially leading to a zero reading depending on the rest of the circuit.
Step 2
B a reduction in the resistance of P
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Answer
Decreasing the resistance of P will increase the current flowing through the circuit, but it may not directly affect the voltmeter reading related to the thermistor.
Step 3
C an increase in the resistance of Q
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Increasing the resistance of Q would cause a higher potential difference across other components, which could lead to a non-zero voltmeter reading.
Step 4
D a reduction in the resistance of R
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Reducing the resistance of R would allow more current to flow, which could balance out the changes caused by the thermistor, thus restoring the voltmeter to zero.
