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 state Faraday’s law, ℰ = −N dΦ_B/dt, and explain why a steady flux induces no emf. (Guide: “Faraday’s law”; Practice Q6(d))
- I can state Lenz’s law and explain that the induced field opposes the change in flux, not the field itself. (Guide: “Lenz’s law: the direction”)
- I can explain that a changing magnetic field creates a non-conservative electric field, ∮E·dl = −dΦ_B/dt, even where there is no wire. (Guide: “Induced electric fields”)
- I can describe how Maxwell’s equations predict electromagnetic waves at c = 1/√(μ₀ε₀), without deriving it. (Guide: “Maxwell’s equations and light”)
Calculation and skills
- I can find the emf when B changes at constant area, including a B(t) I must differentiate. (Guide: Worked example 1; Practice Q4)
- I can find the emf when the area changes in a constant field, for a sliding rod or a changing loop. (Guide: Worked example 2; Practice Q5)
- I can find the emf of a rotating coil, ℰ = NBAω sin ωt. (Guide: “Three ways to change the flux”; Practice Q3)
- I can turn a graph of flux against time into a graph of emf against time. (Guide: Figure 2; Practice Q2)
- I can find the induced electric field inside and outside a solenoid whose field is changing. (Guide: Worked example 3)
- I can combine a flux integral with Faraday’s law for a time-dependent current, and find the total charge that flows. (Practice Q7)
Reasoning and experiments
- I can find the direction of an induced current using Lenz’s law and the right-hand rule. (Guide: Figure 1; Practice Q1, Q4, Q5, Q7)
- I can predict a factor of change in emf when N, B, A or ω changes. (Practice Q3, Q5(c))
- I can design a measurement of induced emf, plot a linear graph and use its gradient. (Guide: “Measuring an induced emf”; Practice Q6)
All ticked? Move on to Topic 13.3, Induced Currents and Magnetic Forces, or return to the course roadmap.