A frost-protection unit contains two resistive heating elements, P and Q. The elements are connected on separate parallel branches.
| Quantity | Value |
|---|---|
| Supply potential difference | 24 V |
| Total current from the supply | 2.20 A |
| Resistance of element P | 15 Ω |
Calculate the resistance of element Q.
A third heating element of resistance 60 Ω is added on another parallel branch.
Calculate the new total current from the supply.
Give the effect of adding the third element on the total resistance of the circuit.
Justify your answer.
94 exam-style questions on AQA GCSE Physics 2.2 Series and parallel circuits, covering 2.2 Series and parallel circuits. Each one has a worked solution and a mark scheme showing where the marks go.