An automated irrigation controller has a circuit with two junctions, X and Y. The measured currents are shown below.
| Location or description | Current |
|---|---|
| Branch leaving junction X | 0.31 A |
| Separate branch entering junction Y | 0.19 A |
| First branch leaving junction Y | 0.37 A |
| Second branch leaving junction Y | 0.46 A |
The current continuing from X reaches Y. At Y, the separate branch joins it before the current divides between the two branches leaving Y.
What is the current approaching junction X?
0.64 A0.64\ \mathrm{A}0.64 A
0.33 A0.33\ \mathrm{A}0.33 A
0.95 A0.95\ \mathrm{A}0.95 A
0.83 A0.83\ \mathrm{A}0.83 A
81 exam-style questions on Edexcel GCSE Physics 10.2 Resistance, covering 10.2.1 Current in a circuit and conservation at junctions, 10.2.2 Resistance and variable resistors, 10.2.3 Series and parallel resistance, 10.2.4 I–V characteristics of components, and 10.2.5 LDRs and thermistors. Each one has a worked solution and a mark scheme showing where the marks go.