Available practice: 75 of 80 marks. Parts 8(b), 10(d) await marking support. Scores cover available parts only.
Fig. 10.1 shows a simplified circuit diagram for an electric oven. The oven contains a fan driven by a motor.
(a)On Fig. 10.1, circle the symbol representing the heater.
[1 mark]
Fig. 10.1 shows a simplified circuit diagram for an electric oven containing a lamp, a heating element in series with a variable resistor, and a fan motor, all in parallel across the power supply. Fig. 10.1 includes a variable resistor.
(b)Explain the function of the variable resistor in this circuit.
Answer guidance
Explain Give reasons, not just what happens. Each distinct reason is usually worth a mark.
[2 marks]
An electric oven contains a fan driven by a motor. The potential difference across the motor is 250 V. The current in the motor is 2.0 A.
(c)Calculate the resistance of the motor.
Answer guidance
Calculate Show your working. The method can earn marks even when the final value is wrong, and a bare answer often cannot.
