An engineer designs a circuit to control an indicator light after a predetermined time delay. Which pair of components is primarily responsible for determining the duration of the time delay in this type of timing circuit?
a diode and a thermistor
a resistor and a capacitor
a transformer and a light-dependent resistor
a transistor and a relay
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.