A student conducts an experiment to determine the electrical characteristics of a fixed resistor, RRR.
The student plots a graph of potential difference VVV on the vertical axis against current III on the horizontal axis.
Explain how this graph can show that the resistor obeys Ohm's law.
At the highest current reading of 1.2 A1.2\text{ A}1.2 A, the plotted potential difference lies slightly above the expected straight line of best-fit. Suggest a physical reason for this observation.
State two ways the student can check if their experimental results are reproducible.
The resistor has a resistance of 15.0 Ω15.0\ \Omega15.0 Ω.
Calculate the power dissipated by the resistor when the current is 0.8 A0.8\text{ A}0.8 A.
Use the equation:
power=(current)2×resistance \text{power} = (\text{current})^2 \times \text{resistance} power=(current)2×resistance42 exam-style questions on OCR GCSE Physics Simple circuits. Each one has a worked solution and a mark scheme showing where the marks go.