Question

Question C. I don' know where to start. I've looked at worked solutions to similar problems but I can't explain why each step was taken.

3. (a) Write down the integral form of Faraday's law (Maxwell's third equation) and briefly explain what is meant by each of the terms in the equation. (3 marks) (b) With reference to Faraday's law, what is meant by the terms motional emf and magnetic induction? (2 marks) (c) Consider a uniform magnetic field that is confined to a circular region with radius R, as shown in the figure below. Suppose the magnitude of B increases with time, i.e., dB/dt > 0. Find the electric field (in terms of dB/dt) induced by the changing magnetic field in the regions (i) <R (ii) r>R. (5 marks) B R

Answer 1

OLD A time varying magnetic inetic field always induced electric field on all space surrounding it sy emp, E. BE TO Also, Es-d0 CF Ø Ê. = -do at so at for 8<R We have & Eenside - de -dd #(8.4) A dB any point at E muide s te (78²) dB I do (the induced electric fields, E at circle will be same) 80, (Elmirde x 20 r=-61772) do Emside =- dB at the ४ 2 Answer

for r>R OTU 2 autorde ai PE = -do at A dB dt - TR² dB at Eoutside (270) - Eoutside -R² dB Answer ar at