An engineer designs a potential divider circuit for a temperature-monitoring system. The system needs to detect when the surroundings become too cold, turning on a heater.
Which component does the engineer need for the potential divider, in addition to a variable resistor, to sense the temperature change?
light-dependent resistor
relay
thermistor
diode
136 exam-style questions on CIE IGCSE Physics 4.3 Electric circuits, covering 4.3.1a Circuit diagrams and circuit components, 4.3.2a Series circuits, 4.3.2b Parallel circuits, 4.3.2c Current and potential difference in circuits, 4.3.2d Combined resistance of resistors in parallel, and 4.3.3 Action and use of circuit components. Each one has a worked solution and a mark scheme showing where the marks go.