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, using charge conservation, why capacitors in series carry the same charge. (Guide: “Capacitors in combination”, Figure 1; Practice Q2)
- I can explain why the equivalent capacitance of a series group is smaller than its smallest capacitor. (Guide: “Capacitors in combination”; Practice Q1)
- I can describe how charge, ΔV_C, current and stored energy change while a capacitor charges and while it discharges. (Guide: “Charging a capacitor through a resistor”, “Discharging a capacitor”; Practice Q6b, Q7c)
- I can explain why an uncharged capacitor acts like a wire at first and a charged one like a break after a long time. (Guide: “Charging a capacitor through a resistor”; Practice Q3, Q7b)
- I can explain what τ = RC means using the 63% and 37% benchmarks, and why the emf does not affect it. (Guide: “The time constant τ = RC”; Practice Q4)
Calculation and skills
- I can find the equivalent capacitance of a series-parallel network and the charge and ΔV on each capacitor. (Guide: Worked example 1; Practice Q5)
- I can calculate τ and check that Ω × F gives seconds. (Practice Q4, Q6a)
- I can sketch ΔV_C–t and I–t graphs for charging and discharging, with the start, τ and long-time values marked. (Guide: Figure 2; Practice Q6b)
- I can find τ from a graph of discharge data and use it to find R or C. (Guide: Worked example 3; Practice Q6d)
- I can plan a measurement of τ with a voltmeter and a timer. (Practice Q6d)
Reasoning
- I can find every current just after a switch closes and after a long time in a circuit with branches. (Guide: Worked example 2; Practice Q7a, Q7b)
- I can predict how changing R or C changes the graphs, and which final values stay the same. (Practice Q6c)
- I can explain what happens when a battery is disconnected from a charged capacitor that still has a resistive path. (Practice Q7c)
All ticked? Move on to Topic 12.1, Magnetic Fields, or return to the course roadmap.