The figure below shows a simplified circuit diagram for a fan-assisted electric oven. The fan is driven by a motor.
On the figure, circle the symbol representing the heater.
The figure above includes a variable resistor.
State the function of a variable resistor.
Suggest how using a variable resistor can affect the heater.
The potential difference across the motor is 
. The current in the motor is 
. Calculate the resistance of the motor.
State the name of component X and explain how it contributes to the safety of the user.
