AP Physics C: Electricity & Magnetism

A complete, visual study guide covering every topic on the College Board AP Physics C E&M exam. Master electrostatics, circuits, magnetism, induction, and Maxwell's equations.

5 Units
24 Topics
~75 Practice Questions
90 min Exam Length

๐Ÿซ College Board Unit Mapping

The College Board organizes AP Physics C: E&M into 6 units (Units 8-13, continuing from Mechanics Units 1-7). This study guide reorganizes the content into 5 logical units. Here's how they map:

Study Guide College Board Units CB Exam Weight
Unit 1: Electrostatics Unit 8: Electric Charges, Fields, Gauss's Law
Unit 9: Electric Potential
Unit 10: Conductors & Capacitors
15-25% + 10-20% + 10-15%
Unit 2: Electric Circuits Unit 11: Electric Circuits 15-25%
Unit 3: Magnetic Fields Unit 12: Magnetic Fields & Electromagnetism 10-20%
Unit 4: Electromagnetism Unit 13: Electromagnetic Induction 10-20%
Unit 5: Maxwell's Equations Distributed across Units 12-13 Integrated above
Note: This guide covers ALL content from the official College Board CED. Unit numbers differ but nothing is omitted.
Unit 1 15โ€“25%

Electrostatics

Coulomb's Law, electric fields, Gauss's Law, electric potential, continuous charge distributions, conductors, and capacitors.

Unit 2 17โ€“23%

Electric Circuits

Current, resistance, Ohm's law, series & parallel circuits, RC circuits in steady-state and transient analysis.

Unit 3 17โ€“23%

Magnetic Fields

Magnetic forces on charges and wires, Biot-Savart Law, Ampere's Law, solenoids, and torque on current loops.

Unit 4 14โ€“20%

Electromagnetism

Magnetic flux, Faraday's Law, Lenz's Law, motional EMF, inductance, and RL & LC circuits.

Unit 5 14โ€“17%

Maxwell's Equations

The four Maxwell equations, displacement current, electromagnetic waves, and unification of E&M.

โŒจ๏ธ Keyboard Shortcuts

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๐Ÿ“ Exam Strategy & Tips

โฑ๏ธ Time Management

  • Section I: 35 MC questions in 45 minutes (~77 sec each)
  • Section II: 3 FRQs in 45 minutes (15 min each)
  • Skip hard MC questions โ€” come back if time permits
  • Leave 5 minutes at the end to bubble in skipped answers

โœ๏ธ FRQ Strategy

  • Read all parts before starting โ€” later parts often give hints
  • Show ALL work: equation โ†’ substitution โ†’ answer with units
  • If you can't solve part (a), state an assumed answer and use it for (b)-(d)
  • Draw clear diagrams โ€” they earn partial credit
  • Justify direction claims with "by Lenz's Law" or "by RHR"

๐Ÿ”ฌ Lab-Based FRQ Tips

  • Expect 1 lab-design or data-analysis FRQ
  • Know how to linearize: plot Q vs V (for C), Tยฒ vs m (for oscillations)
  • Slope interpretation: slope = C, slope = 4ฯ€ยฒ/k, etc.
  • Error analysis: mention systematic vs random uncertainty sources

๐Ÿงฎ Calculator Policy

  • 4-function, scientific, or graphing calculator allowed
  • No calculator with QWERTY keyboard or internet access
  • Store constants: k, ฮตโ‚€, ฮผโ‚€, e, m_e, m_p
  • Practice unit conversions: ฮผCโ†’C, cmโ†’m, msโ†’s
Most Common Mistakes: (1) Forgetting to square r in Coulomb's/Biot-Savart Law (2) Using series rules for parallel circuits (3) Forgetting the minus sign in Faraday/Lenz (4) Wrong RHR direction for negative charges (5) Confusing capacitor open/short at t=0 vs t=โˆž.

๐Ÿค“ Interactive Practice

Test your knowledge with interactive multiple-choice questions (with instant feedback) and free-response questions (with toggle-able solutions). Progress is saved automatically.

Practice 112 MCQ + 5 FRQ

Electrostatics

Coulomb's Law, fields, Gauss's Law, potential, capacitors.

Practice 210 MCQ + 5 FRQ

Electric Circuits

Ohm's Law, Kirchhoff's Rules, RC circuits, power, resistivity.

Practice 310 MCQ + 5 FRQ

Magnetic Fields

Magnetic forces, Biot-Savart, Ampere's Law, torque, solenoids.

Practice 410 MCQ + 5 FRQ

EM Induction

Faraday's Law, Lenz's Law, motional EMF, inductance, RL/LC circuits.

Practice 58 MCQ + 3 FRQ

Maxwell's Equations

The four equations, displacement current, EM waves, Poynting vector.