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 inductance as opposition to a change in current, using Faraday’s and Lenz’s laws. (Guide: “A coil that resists change in its own current”)
- I can explain why straight wires are modelled as having zero inductance while a solenoid is an inductor. (Practice Q6)
- I can state and use the units of inductance, including 1 H = 1 V·s/A. (Practice Q1)
- I can explain why the current through an inductor cannot change instantly. (Guide: “The self-induced emf”)
Calculation and skills
- I can derive L = μ₀N²A/ℓ for a long solenoid from its magnetic field. (Guide: “The inductance of a long solenoid”; Practice Q6)
- I can calculate L with and without a core of given permeability. (Guide: Worked example 1; Practice Q6)
- I can find the size and direction of a self-induced emf from a rate of change of current. (Practice Q3, Q6)
- I can differentiate a given I(t) to find ℰ(t), and sketch ℰ against t from a graph of I against t. (Guide: Figure 1, Worked example 2; Practice Q5)
- I can derive U = ½LI² and use it to find stored and released energy. (Guide: “Energy stored in an inductor”; Practice Q4)
Reasoning
- I can predict how L changes when N, ℓ, r or the core changes. (Guide: scaling table; Practice Q2)
- I can use energy conservation to follow energy from an inductor into a resistor or a capacitor. (Practice Q7)
- I can explain why the emf is zero when the current is at its maximum. (Practice Q5)
All ticked? Move on to Topic 13.5, Circuits with Resistors and Inductors (LR Circuits).