(a)[2]
In Fig. 7.1, sketch the temperature characteristic of a negative temperature coefficient (n.t.c.) thermistor. Put the quantity and unit on each axis.
(b)[2]
An n.t.c. thermistor and a resistor are arranged as shown in Fig. 7.2. The thermistor’s temperature is increased. State and explain the change, if any, in the voltmeter reading.
(c)[3]
Fig. 7.3 shows how the fractional change in resistance $\Delta R / R$ for a strain gauge varies with the fractional change in length $\Delta x / x$. The gauge’s unstrained resistance is $120\,\Omega$. Calculate the new resistance of the gauge when it is extended to a strain of $0.020$.