An engineer investigates how the current in a new tungsten-alloy micro-heating element, component SSS, varies with the potential difference (voltage) across it.
The table shows the engineer's results:
| Voltage across SSS (V) | Current in SSS (A) |
|---|---|
| 0.0 | 0.00 |
| 1.5 | 0.45 |
| 3.0 | 0.82 |
| 4.5 | 1.10 |
| 6.0 | 1.30 |
| 7.5 | 1.42 |
State the equation linking voltage, current, and resistance.
The engineer plots a graph of current on the y-axis against voltage on the x-axis and draws a curve of best fit. At a voltage of 3.6 V, the current read from the graph is 0.94 A.
Calculate the resistance of component S S\,S at this voltage. Give your answer to 2 significant figures and state the unit.
Describe how the resistance of component S S\,S changes as the voltage increases. Explain this change.
25 exam-style questions on Edexcel IGCSE Physics Energy and voltage in circuits. Each one has a worked solution and a mark scheme showing where the marks go.