Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can describe the field around a long straight wire as circles centred on the wire, with no part towards, away from or along it. (Guide: “The field around a long straight wire”, Figure 1; Practice Q1)
- I can use the right-hand rule to find the direction of the field at any point near a straight wire. (Guide: Figure 1; Practice Q1, Q6)
- I can find the direction of the field at the centre of a current loop. (Guide: “The field at the centre of a loop”; Practice Q4)
- I can explain why a magnetic field exerts a force on a current-carrying wire, starting from the force on moving charges. (Guide: “The force on a current-carrying wire”)
Calculation and skills
- I can calculate B = μ₀I/(2πr) and predict how B changes when I or r changes. (Guide: “The field around a long straight wire”; Practice Q2)
- I can add the fields of two or more wires as vectors, including fields that are opposite or perpendicular. (Guide: Worked example 1; Practice Q6)
- I can calculate the force F = IℓB sin θ on a wire and find its direction with the right-hand rule. (Guide: Worked example 2; Practice Q5)
- I can find the force per unit length between two parallel wires and say whether they attract or repel. (Guide: “Two parallel wires”; Practice Q3)
- I can choose axes that give a straight-line graph (B against 1/r, or F against I) and use the slope to find an unknown. (Guide: Worked example 3; Practice Q7)
Reasoning
- I can explain why two wires exert equal forces on each other even when their currents differ. (Practice Q3)
- I can plan an experiment to test how the field of a wire depends on current or distance, including how to deal with Earth’s field. (Guide: “Designing the experiment”; Practice Q7)
- I can evaluate a claim that adds field magnitudes without considering direction. (Practice Q6c)
All ticked? Move on to Topic 12.4, Electromagnetic Induction and Faraday’s Law, with the Topic 12.4 study guide, or return to the course roadmap.