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In the circuit below, the initial voltmeter reading is zero - AQA - A-Level Physics - Question 26 - 2019 - Paper 1
Question 26
In the circuit below, the initial voltmeter reading is zero. The temperature of the negative temperature coefficient thermistor T is then increased. Which change t... show full transcript
Worked Solution & Example Answer:In the circuit below, the initial voltmeter reading is zero - AQA - A-Level Physics - Question 26 - 2019 - Paper 1
Step 1
The temperature of the negative temperature coefficient thermistor T is then increased.
Answer
When the temperature of thermistor T is increased, its resistance decreases, which can lead to a change in the overall current in the circuit. To restore the voltmeter reading to zero, we need to make a change that compensates for this decrease in resistance.
Among the options provided, increasing the resistance of component R would oppose the decrease in the circuit and could potentially balance out the current, restoring the voltmeter reading to zero. Therefore, the correct option is:
B. Increasing the resistance of R.