← Physics C: Electricity and Magnetism syllabus

United StatesPhysics C: Electricity and Magnetism

Unit 12: Magnetic Fields and Electromagnetism

4 dot points across 4 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How does Ampere's law use symmetry to find the magnetic field of a current distribution?

Topic 12.4 Ampere's Law: apply Ampere's law with a chosen Amperian loop to find the field of wires, solenoids and toroids.
A calculus-based answer to AP Physics C E&M Topic 12.4, covering Ampere's law as a line integral, choosing an Amperian loop, and deriving the field of a long wire, a solenoid and a toroid.
11 min answer →

How does the Biot-Savart law give the magnetic field of a current, and how is it applied to wires and loops?

Topic 12.3 Magnetic Fields of Current-Carrying Wires and the Biot-Savart Law: use the Biot-Savart law to find the field of current elements, straight wires and loops.
A calculus-based answer to AP Physics C E&M Topic 12.3, covering the Biot-Savart law, the field of a current element, integration for a straight wire and a circular loop on its axis, and the force between parallel wires.
12 min answer →

What is a magnetic field, how is it represented, and how does it differ from an electric field?

Topic 12.1 Magnetic Fields: describe magnetic fields, their sources in moving charges and magnets, field-line representation, and the absence of magnetic monopoles.
A calculus-based answer to AP Physics C E&M Topic 12.1, covering the magnetic field, its sources in moving charge, dipoles and field lines, Gauss's law for magnetism, and how magnetic fields differ from electric fields.
9 min answer →

How does a magnetic field exert a force on a moving charge or a current-carrying wire?

Topic 12.2 Magnetism and Moving Charges: apply the magnetic force on moving charges and currents, including circular motion and the force on a wire.
A calculus-based answer to AP Physics C E&M Topic 12.2, covering the magnetic force on a moving charge, the right-hand rule, circular motion in a field, the force on a current-carrying wire, and combined electric and magnetic forces.
11 min answer →