Two properties of an ideal operational amplifier (op-amp) are infinite input impedance and infinite bandwidth. State what is meant by:
infinite input impedance
infinite bandwidth.
A student uses a negative temperature coefficient thermistor in the circuit shown in the figure below to indicate changes in temperature.
Show that the potential at point X is 
.
The thermistor has a resistance of 
at a particular temperature. For this temperature of the thermistor, calculate the magnitude of the reading on the voltmeter.
The temperature of the thermistor increases. State and explain the effect of this change on the magnitude of the reading on the voltmeter.
Explain why the amplifier circuit will no longer indicate temperature changes when the magnitude of the gain of the circuit is greater than 
.
.
is 
. So at a gain above 
