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 explain resistance as the opposition an object gives to the movement of charge, and define it as R = ΔV/I. (Guide: “What resistance measures”)
- I can explain the difference between resistivity (a property of a material) and resistance (a property of an object). (Guide: “Resistance from shape and material”)
- I can explain why the resistivity of a metal usually increases with temperature. (Guide: “Resistivity and temperature”; Practice Q3, Q6)
- I can say what makes an element ohmic, and explain why a filament bulb is not. (Guide: “Ohm’s law and ohmic elements”; Practice Q3)
- I can explain that a resistor converts electrical energy into thermal energy without using up current. (Guide: “What resistance measures”)
Calculation and skills
- I can calculate R from ρ, L and a diameter, converting mm and mm² correctly. (Guide: Worked example 1; Practice Q4, Q5)
- I can predict the factor by which R and I change when length, diameter or material change. (Guide: Worked example 2; Practice Q1, Q5c)
- I can use I = ΔV/R to find any one of the three quantities. (Practice Q5b)
- I can find R from the slope of an I–ΔV graph, remembering that the slope is 1/R. (Guide: “Reading resistance from a graph”; Practice Q2, Q7)
- I can plot R against L and use the slope to find a resistivity. (Guide: Worked example 3)
Reasoning
- I can plan an experiment to measure the resistance of an element, placing the ammeter and voltmeter correctly. (Guide: “Measuring resistance in the lab”; Practice Q6a)
- I can use data or a graph to decide whether an element is ohmic. (Practice Q6c)
- I can evaluate a claim that changing ΔV changes the resistance of an ohmic element. (Practice Q7c)
All ticked? Move on to Topic 11.4, Electric Power, or return to the course roadmap.