Skip to content
fivefold
Start free
All courses
Physics C: E&M

AP Physics C: Electricity and Magnetism

Calculus-based electricity and magnetism: Gauss and Ampère, circuits that change in time, and induction, argued the way AP readers score it.

Category
Sciences
Units
6 units
Exam
Exam May 5, 2027 (in 220 days)
Start Unit 1 freeSign in

Unit 1 is free with an account. No card, no trial clock.

What the course covers

A calculus-based college electricity and magnetism course built on the current framework (CED effective Fall 2024, with the exam changes that take effect in May 2027). Six units, numbered 8 through 13 in the College Board framework because they follow Mechanics, run from charges, fields, and Gauss's law through electric potential, conductors and capacitors, circuits (including RC circuits), magnetic fields with the Biot-Savart and Ampère laws, and electromagnetic induction with LR and LC circuits. Calculus does the real work here: fields of rods, rings, and arcs by integrating dqdq, enclosed charge from a nonuniform density, potential from −∫E⃗⋅dr⃗-\int \vec{E}\cdot d\vec{r}, the exponential solutions of RC and LR loop equations, flux integrals, and the simple harmonic equation of an LC circuit. Every lesson trains the four free-response tasks by name (Mathematical Routines, Translation Between Representations, Experimental Design and Analysis, and Qualitative/Quantitative Translation), including derivations that begin from a sheet equation, field and force arrows, graph sketches whose features match the math, linearized lab graphs, and justifications that go beyond "because of Lenz's law". The Wednesday, May 5, 2027 exam has 42 four-choice multiple-choice questions in Bluebook (85 minutes) and four handwritten free-response questions (95 minutes), with a calculator and the official equation sheet throughout.

6 units, with exam weights

  1. Unit 1

    Electric Charges, Fields, and Gauss's Law

    15-25% of examFree
    CED Unit 8, tied for the heaviest unit on the exam. Charge and Coulomb's law, charging and polarization, electric fields of point charges and field maps, fields of continuous charge distributions by integration (rods, rings, arcs, infinite lines), electric flux as a surface integral, and Gauss's law for spherical, cylindrical, and planar symmetry, including nonuniform charge densities.
    6 topics
    1. 8.1Electric Charge and Electric Force
    2. 8.2Conservation of Electric Charge and the Process of Charging
    3. 8.3Electric Fields
    4. 8.4Electric Fields of Charge Distributions
    5. 8.5Electric Flux
    6. 8.6Gauss's Law

  2. Unit 2

    Electric Potential

    10-20% of exam
    CED Unit 9. Electric potential energy of pairs and systems of charges, electric potential of point charges and continuous distributions, the two-way relationship between field and potential (derivative and path integral), equipotential maps, and conservation of energy for charged particles moving through potential differences.
    3 topics
    1. 9.1Electric Potential Energy
    2. 9.2Electric Potential
    3. 9.3Conservation of Electric Energy

  3. Unit 3

    Conductors and Capacitors

    10-15% of exam
    CED Unit 10. Conductors in electrostatic equilibrium (surface charge, zero interior field, equipotential surfaces, shielding), charge sharing between connected conductors and grounding, capacitance of parallel-plate, spherical, and cylindrical capacitors derived from Gauss's law, energy stored in a capacitor, and how dielectrics change field, potential difference, capacitance, and energy.
    4 topics
    1. 10.1Electrostatics with Conductors
    2. 10.2Redistribution of Charge Between Conductors
    3. 10.3Capacitors
    4. 10.4Dielectrics

  4. Unit 4

    Electric Circuits

    15-25% of exam
    CED Unit 11, tied for the heaviest unit and the one with the most topics. Current as a flow of charge (drift velocity, current density), circuit schematics, resistance and resistivity, Ohm's law, power and bulb brightness, series and parallel combinations, real batteries and meters, Kirchhoff's loop and junction rules, equivalent capacitance, and RC circuits solved from their differential equations.
    8 topics
    1. 11.1Electric Current
    2. 11.2Simple Circuits
    3. 11.3Resistance, Resistivity, and Ohm's Law
    4. 11.4Electric Power
    5. 11.5Compound Direct Current Circuits
    6. 11.6Kirchhoff's Loop Rule
    7. 11.7Kirchhoff's Junction Rule
    8. 11.8Resistor-Capacitor (RC) Circuits

  5. Unit 5

    Magnetic Fields and Electromagnetism

    10-20% of exam
    CED Unit 12. Magnetic fields and dipoles, magnetic materials and permeability, fields made by moving charges, the magnetic force on moving charges and on currents (with circular orbits, velocity selectors, and the Hall effect), the Biot-Savart law for segments and loops, and Ampère's law for wires, solenoids, and conductors with a current density.
    4 topics
    1. 12.1Magnetic Fields
    2. 12.2Magnetism and Moving Charges
    3. 12.3Magnetic Fields of Current-Carrying Wires and the Biot-Savart Law
    4. 12.4Ampère's Law

  6. Unit 6

    Electromagnetic Induction

    10-20% of exam
    CED Unit 13. Magnetic flux, Faraday's law for changing field, area, or orientation, Lenz's law for direction, magnetic forces on induced currents and the motion they cause, inductance and energy stored in inductors, LR circuits solved from their differential equations, and LC circuits as electrical simple harmonic oscillators.
    6 topics
    1. 13.1Magnetic Flux
    2. 13.2Electromagnetic Induction
    3. 13.3Induced Currents and Magnetic Forces
    4. 13.4Inductance
    5. 13.5Circuits with Resistors and Inductors (LR Circuits)
    6. 13.6Circuits with Capacitors and Inductors (LC Circuits)

The exam, part by part

5 parts, 3 h in all.

  • Section I: Multiple Choice

    Questions
    42
    Time
    1 h 25 min
    Weight
    50%

    Calculator allowed

    Format details

    Answered in the Bluebook app. Four answer choices (A-D). Discrete questions and short sets of two or three questions that share a stimulus. All six units appear, weighted Unit 8 15-25%, Unit 9 10-20%, Unit 10 10-15%, Unit 11 15-25%, Unit 12 10-20%, Unit 13 10-20% (platform Units 1-6). By skill: 2.A derive 25-30%, 2.B calculate 20-25%, 2.C compare 10-15%, 2.D predict factors of change 10-15%, 3.B apply a law to make a claim 15-25%, 3.C justify with evidence 5-10%. Science Practice 1 (creating representations) and 3.A (experimental procedures) are not assessed in this section. A four-function, scientific, or graphing calculator is allowed, and the equation sheet is available in print and in Bluebook.

  • Section II, Question 1: Mathematical Routines (MR)

    Questions
    1
    Time
    22.5 min
    Weight
    12.5%

    Calculator allowed

    Format details

    Task types: Mathematical Routines

    Section II is one 95-minute block of four questions in a fixed order, viewed in Bluebook and handwritten in a paper booklet; students may move between questions. The CED suggests 20-25 minutes for this question; 22.5 is the midpoint. College Board does not publish per-question weights; the 50% section weight is split here in proportion to raw points (10 of 40).

  • Section II, Question 2: Translation Between Representations (TBR)

    Questions
    1
    Time
    27.5 min
    Weight
    15%

    Calculator allowed

    Format details

    Task types: Translation Between Representations

    Suggested time 25-30 minutes (midpoint 27.5). Weight in proportion to raw points (12 of 40).

  • Section II, Question 3: Experimental Design and Analysis (LAB)

    Questions
    1
    Time
    27.5 min
    Weight
    12.5%

    Calculator allowed

    Format details

    Task types: Experimental Design and Analysis

    Suggested time 25-30 minutes (midpoint 27.5). Weight in proportion to raw points (10 of 40). Students plot data by hand on a provided grid; a ruler or straightedge is allowed.

  • Section II, Question 4: Qualitative/Quantitative Translation (QQT)

    Questions
    1
    Time
    17.5 min
    Weight
    10%

    Calculator allowed

    Format details

    Task types: Qualitative/Quantitative Translation

    Suggested time 15-20 minutes (midpoint 17.5). Weight in proportion to raw points (8 of 40). The 2025 mean was 4.57 of 8.

How the 1 to 5 score is set

Section I (42 multiple-choice questions, no penalty for wrong answers) and Section II (four free-response questions, 40 raw points: MR 10, TBR 12, LAB 10, QQT 8) each count for half of a weighted composite score. College Board converts the composite to the 1-5 AP score with cut points set each year from statistical equating and college-grade comparability studies; the cuts are not published. On the May 2025 exam (29,910 students), 25.1% earned a 5, 23.6% a 4, and 24.1% a 3 (mean 3.37); the free-response means were MR 4.43/10, TBR 7.76/12, LAB 7.37/10, and QQT 4.57/8. Free-response points are awarded row by row, each row worth 1 point, and a correct final answer with no multistep derivation from a sheet equation typically earns only the answer point.

What you bring and get

The AP Physics C: Electricity and Magnetism Table of Information (constants and conversion factors including kk, ε0\varepsilon_0, μ0\mu_0, ee, and particle masses; unit symbols; prefixes; trig values for common angles; the exam conventions; the full Electricity and Magnetism equation table; the full Mechanics equation table; geometry and trigonometry, vectors, calculus rules, and identities) is printed for every student and also available in Bluebook for both sections. A four-function, scientific, or graphing calculator is allowed on both sections, and Bluebook includes a built-in graphing calculator. A ruler or straightedge is allowed for free response. Exam conventions: frames are inertial, air resistance is negligible, springs and strings are ideal, the electric potential is zero infinitely far from an isolated point charge, current is in the direction positive charges would drift, and batteries, wires, and meters are ideal, unless a question says otherwise.

Skills the exam scores

  • 1.ACreate diagrams, tables, charts, or schematics

    Science Practice 1, Creating Representations (20-35% of free response, not assessed in multiple choice). Represent an E&M situation: arrows on a dot for the direction of an electric or magnetic field, force, or acceleration; direction symbols for fields into or out of the page; a circuit schematic with standard symbols; field-line or equipotential maps; bar charts of emf or energy.

  • 1.BCreate quantitative graphs and plot data

    Science Practice 1, Creating Representations (free response only). Choose quantities that linearize a model, label axes with units, pick linear numerical scales, plot data accurately, and draw a best-fit line, most often in the LAB question (resistance versus length, period versus C\sqrt{C}, potential difference versus dI/dtdI/dt).

  • 1.CSketch qualitative graphs of a model or system

    Science Practice 1, Creating Representations (free response only). Sketch field, potential, current, charge, flux, emf, or power versus position or time so the graph shows the right starting value, sign, zeros, slope, concavity, asymptotes, discontinuities, and number of cycles, matching the dependence derived elsewhere in the question.

  • 2.ADerive a symbolic expression

    Science Practice 2, Mathematical Routines (25-30% of multiple choice; Practice 2 is 40-45% of free response). Start from Coulomb's, Gauss's, Ampère's, Faraday's, or Kirchhoff's law or another reference-sheet equation and follow a logical algebraic or calculus pathway, with correct limits, to an expression in the allowed variables.

  • 2.BCalculate or estimate a quantity with units

    Science Practice 2, Mathematical Routines (20-25% of multiple choice). Compute a numerical value (a field, potential, capacitance, current, time constant, induced emf) from known quantities by a logical computational pathway, with correct units and sensible significant figures.

  • 2.CCompare quantities across scenarios or times

    Science Practice 2, Mathematical Routines (10-15% of multiple choice). Compare a physical quantity between two or more scenarios, or at different times or places in one scenario, by magnitude, ratio, or ranking (bulb brightness, fields at two points, charge before and after a dielectric).

  • 2.DPredict values or factors of change from functional dependence

    Science Practice 2, Mathematical Routines (10-15% of multiple choice). Use how one variable depends on another (inverse square, inverse, logarithmic, exponential, linear) to predict a new value or the factor by which a quantity changes when a side length, radius, resistance, or number of turns changes.

  • 3.ACreate an experimental procedure for a question

    Science Practice 3, Scientific Questioning and Argumentation (free response only; Practice 3 is 30-35% of free response). Design a procedure a high school lab could run with realistic equipment (meters placed correctly, a variable power supply, capacitors of known capacitance, a force sensor): vary one parameter, measure its effect on one quantity, reduce uncertainty, and say how the data answer the question.

  • 3.BApply a law, definition, or model to make a claim

    Science Practice 3, Scientific Questioning and Argumentation (15-25% of multiple choice). Choose the principle that governs a situation (superposition, Gauss's law, conservation of energy or charge, Kirchhoff's rules, Faraday's and Lenz's laws) and use it to reach a claim.

  • 3.CJustify a claim with evidence or principles

    Science Practice 3, Scientific Questioning and Argumentation (5-10% of multiple choice). Support or refute a claim with data, a representation, or a physical law, using conceptual reasoning that goes beyond restating an equation or naming a law. The CED's own example: saying an induced current is clockwise "because of Lenz's law" is not enough for credit; the answer must use the right-hand rule and the opposition to the change in flux. The 2025 Chief Reader report shows where points go: fewer than half of responses justified a bar chart and a power graph as consistent by relating power to the square of the emf, and many force comparisons omitted the field directions at each location or the fact that the charges and velocities were equal.