What the syllabus asks you to cover
Biot-Savart’s law, Magnetic field intensity and flux density Ampere’s circuital law and its application, Physical significance of curl, Stoke’s theorem. Magnetic force, magnetic torque, magnetic moment, magnetic dipole, magnetization. Magnetic boundary condition.
Start here for the core ideas. A dedicated GitBook topic page was not available; this original guide is introductory. Use the syllabus checklist and references below to study the remaining details.
Build the magnetic model
Magnetic flux density and magnetic field intensity are related by for a linear, isotropic material. Biot–Savart's law calculates the field produced by a current element; Ampère's law is especially useful when symmetry makes a closed path easy to choose. Magnetic flux is the surface integral of the normal component of flux density.
Link fields and circuits
Faraday's law relates changing flux linkage to induced electromotive force: . The minus sign is Lenz's law: the induced effect opposes the change that caused it. Distinguish self-inductance from mutual inductance. Magnetic energy in a linear inductor is .
Try it
For and , stored energy is 9 mJ. Doubling current multiplies that energy by four.
Check your understanding
Why is magnetic flux through a closed surface zero? Explain how material permeability and the boundary conditions change a magnetic-circuit calculation. Study forces on moving charges and current-carrying conductors next.
Pause and recall
Without looking back, explain the main idea, recall a key definition or formula, and describe when it applies. Include assumptions and units where relevant. Revisit any step you could not explain.