Alternative to Practical: show readings, units and working. For a plotted graph or diagram, upload a clear image of your work on the supplied figure.
(a)Read question and case materials as text
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A student investigates a thermistor in the circuit of Fig. 2.1. The supply, switch, resistor and thermistor are connected as shown, with a voltmeter across the thermistor.
Draw a circuit diagram corresponding to the physical circuit in Fig. 2.1: battery, switch, fixed resistor, thermistor and voltmeter.
A student investigates a thermistor in the circuit of Fig. 2.1. The supply, switch, resistor and thermistor are connected as shown, with a voltmeter across the thermistor.
Fig. 2.1
Draw a circuit diagram corresponding to the physical circuit in Fig. 2.1: battery, switch, fixed resistor, thermistor and voltmeter.
Answer guidance
Draw Accuracy is being marked. Use the figure and be precise about position and labels.
[3 marks]
(b)Read question and case materials as text
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A student investigates a thermistor in the circuit of Fig. 2.1. The supply, switch, resistor and thermistor are connected as shown, with a voltmeter across the thermistor.
Fig. 2.2 records room temperature T_W = 20 °C. Read the voltmeter in Fig. 2.3 and record V_W in V.
Fig. 2.2 records room temperature T_W = 20 °C. Read the voltmeter in Fig. 2.3 and record V_W in V.
Fig. 2.2Fig. 2.3
[1 mark]
(c)Read question and case materials as text
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A student investigates a thermistor in the circuit of Fig. 2.1. The supply, switch, resistor and thermistor are connected as shown, with a voltmeter across the thermistor.
Fig. 2.4 records ice-water temperature T_C = 0 °C. Read the thermistor voltmeter in Fig. 2.5 and record V_C in V.
Fig. 2.4 records ice-water temperature T_C = 0 °C. Read the thermistor voltmeter in Fig. 2.5 and record V_C in V.
Fig. 2.4Fig. 2.5
[1 mark]
(d)(i)
Use V_C = 2.9 V, V_W = 2.0 V, T_W = 20 °C and T_C = 0 °C to calculate average voltage change per degree ΔV_AV = (V_C − V_W)/(T_W − T_C). State the unit.
Answer guidance
Using You must use the thing it names. An answer that reaches the right value another way may not score.
[2 marks]
(d)(ii)
Use ΔV_AV from (d)(i) to predict thermistor voltage V_PB at body temperature 37 °C. Assume the average change per degree is constant; V_W = 2.0 V at 20 °C.
Answer guidance
Using You must use the thing it names. An answer that reaches the right value another way may not score.
[1 mark]
(d)(iii)Read question and case materials as text
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A student investigates a thermistor in the circuit of Fig. 2.1. The supply, switch, resistor and thermistor are connected as shown, with a voltmeter across the thermistor.
Fig. 2.6 gives measured thumb-and-forefinger voltage V_AB = 0.80 V. Is it equal to your predicted V_PB within 10%? State a conclusion supported by a calculation.
Fig. 2.6 gives measured thumb-and-forefinger voltage V_AB = 0.80 V. Is it equal to your predicted V_PB within 10%? State a conclusion supported by a calculation.
Fig. 2.6
Answer guidance
State A short answer. No explanation is needed, and adding one cannot earn extra marks.
[2 marks]
5054/41/M/J/23Cambridge O Level Physics 5054 · May/June 2023 · Paper 4 variant 1 · Question 2