Physics C: Electricity and Magnetism Study Library.

About the exam

AP Physics C: Electricity and Magnetism is a 1.5-hour exam (taken separately from Mechanics). Section I has 40 multiple-choice in 45 minutes. Section II has 4 free-response questions in 45 minutes (15 pts each, 60 pts total). Calculus is required. A formula sheet is provided.

How to use this library

Each unit page below contains the full list of key topics, common exam errors to avoid, and a study guide section. Work through units in order, or jump directly to the unit with the highest exam weight — those are your highest-leverage study targets.

Exam strategy notes

• Gaussian surface selection is an exam skill. For Gauss's Law, always ask: is $E$ constant in magnitude and parallel to $d\vec{A}$ on my surface? If not, choose a different geometry.
• Faraday's Law sign: $\mathcal{E} = -d\Phi_B/dt$. The negative sign gives Lenz's Law direction — never drop it.
• RC and RL transient circuits: know initial conditions (t = 0) and final conditions (t → ∞) cold. The exponential solution follows from them.
• Maxwell's displacement current $\epsilon_0 \partial\Phi_E/\partial t$ extends Ampère's Law to capacitor gaps. Understand why it's needed conceptually.