AP Physics C Electricity and Magnetism review: format, units, and how to study

What’s on the AP Physics C: E&M exam

The exam splits evenly into two sections. Section I is 42 multiple-choice questions in 85 minutes, worth 50%. Some stand alone; others come in sets that share a diagram or a data set. Section II is four free-response questions in 95 minutes, also 50%, and you write those out by hand. The whole exam runs 3 hours.

The four free-response questions, and what each one is worth

College Board publishes a point value and a suggested time for every free-response question, and it prints them in the Course and Exam Description rather than on its public exam pages. The four always appear in this order:

That is 40 raw points in Section II. College Board prints no total, but the four values it does print add to 40, and the suggested times add to exactly the 95 minutes the section runs. Question 2 carries the most points of the four; Question 4 carries the fewest and gets the least time.

What changed for the 2027 exam

Two numbers moved. College Board’s clarifications document for this course states that the multiple-choice count changed from 40 to 42 and its timing from 80 minutes to 85, while the free-response section came down from 100 minutes to 95. AP Central dates the change to the May 2027 exam. That matters when you time yourself: a released paper from 2026 still prints the old 100-minute directions, so it is a fine source of questions and a poor source of pacing.

Everything else about test day is settled. Calculators are allowed on both sections and the permitted range is wide: four-function, scientific and graphing models all qualify, and Bluebook carries a built-in Desmos one. Of the 44 courses on College Board’s policy table, only three carry a 2027 restriction, and Physics C is not among them. Reference materials are printed and mailed to schools as well as being available in Bluebook, and our AP Physics C Electricity and Magnetism equation sheet shows what is on them. The exam is hybrid: you answer the multiple choice and read the free-response prompts in Bluebook, and handwrite your solutions in a paper booklet that is collected for scoring.

The 6 units of AP Physics C: E&M

The course covers six units, numbered 8 through 13 because the Physics C sequence continues from the seven Mechanics units — so a syllabus that opens at “Unit 8” is not missing anything. The percentages below are College Board’s weightings for the multiple-choice section, which is how it publishes them; it sets no per-unit weighting for the free response at all.

Units 8 and 11 tie at both ends of their range, so electrostatics and circuits are the two you cannot afford to be shaky on. Nothing here tells you how the free response is distributed, and College Board does not say — every one of the four questions can draw on any unit.

How AP Physics C: E&M is scored

Your multiple-choice and free-response points are weighted, combined into one raw score, and converted to a 1–5 composite. College Board is explicit that this is not a curve: the exam is criterion-referenced, so every student who meets the criteria for a 3, 4 or 5 receives it however many students that is. It publishes no cut scores and no conversion table for this exam, so any percentage you see quoted as “what you need for a 5” is somebody’s estimate, including the one our AP Physics C: Electricity and Magnetism score calculator uses.

The outcomes are strong. In 2026, 75% of students scored a 3 or higher and 24% earned a 5. The last complete year is 2025: 72.9% scored a 3 or higher, 25.2% earned a 5, the mean was 3.38, and 29,708 students took it. Read those two figures carefully, though. Across the 40 exams College Board reported in 2026 the pass rate ranks 14th, a little above the field average of 73%; the 5 rate ranks 6th, against a field average of under 20%. It is the proportion of 5s that is unusual here, not the proportion of passes.

One comparison to avoid: 2024 looks easier on the 5 rate (35.2%) and it was a different exam. That year Section II was three 15-point questions; 2025 was the first administration of the current four-question format. Two formats and two cohorts explain neither figure.

Where students actually earn the points

College Board publishes a mean for every free-response question and, in its Chief Reader Report, for every individual point. The 2025 results invert what most students expect:

The lab question was the best-answered on the paper and the mathematical-routines question the worst, 30 percentage points apart. Across the whole section students earned 24.13 of the 40 points. Sorted across all 40 individual points, the three lowest on the 2025 exam were the three capacitance points inside Question 1, at means of 0.26, 0.21 and 0.19. College Board notes that only about a quarter of responses got that part right.

How to study for AP Physics C: E&M

Start where the points are lost. College Board’s reading of 2025 Question 1 is that most students knew to reach for Gauss’s law and then could not set the surface up: responses computed the volume of a Gaussian surface instead of its area, confused surface area with cross-sectional area, or chose a surface whose geometry did not match the charge distribution’s symmetry. Drill the three symmetries until you can say which one a problem wants and why: spherical, cylindrical, planar. That is better use of an hour than another pass through the formula list.

Then be careful with the equation sheet, because it is where the single worst-scoring part of that exam went wrong. College Board records that the most common mistake across every part of Question 1 was reaching for the parallel-plate capacitance relationship precisely because it is printed on the reference sheet, and applying it to a cylindrical capacitor. The sheet removes the need to memorize it; it does not tell you which relationship the geometry allows. Work with it open, and each time you pull an equation off it, say out loud what assumption it carries.

Give the experimental question less anxiety and the derivations more. Students earn about three-quarters of the lab question’s points and under half of the mathematical-routines question’s, which is the reverse of how most study time gets allocated. And note what the multiple choice cannot test: College Board assesses Science Practice 1, which is drawing diagrams, plotting quantitative graphs and sketching qualitative ones, only on the free response, where it is worth 20–35% of the section, and it does the same with creating an experimental procedure. Every drawing point on this exam is a free-response point, so a study plan built only on multiple-choice practice never touches that band at all.

Finally, work whole free-response questions against the clock using the published times of 20–25, 25–30, 25–30 and 15–20 minutes rather than the directions on a 2026 paper, which are pre-2027 and allow five minutes too many.

AP Physics C: E&M vs Mechanics — which is harder?

The two exams now have the same shape: 42 multiple-choice questions in 85 minutes, four free-response questions in 95 minutes, and the same four question types. They differ in the mathematics. Mechanics deals with motion you can picture; E&M works with fields you cannot, and it leans harder on the integral forms of Gauss’s and Ampère’s laws. It is usually taken second, so its pace assumes Mechanics-level fluency.

The scores do not say E&M is the harder paper. In 2026, E&M returned a 75% pass rate and 24% fives against Mechanics’ 72% and 20%; in 2025 the pass rates were 72.9% and 73.2%, with E&M ahead on fives at 25.2% against 21.7%. Both cohorts are small and both are filtered before they arrive: College Board tells students to take a Newtonian physics course and to have taken or be taking calculus. The fairer reading is that these are two comparably hard exams taken by comparably prepared students, and that what makes E&M feel harder is the calculus rather than the outcome. They are separate exams with separate scores, and many students take both in the same year. If that is your plan, our AP Physics C Mechanics review covers the companion course and its seven units.

When is the AP Physics C: E&M exam, and how long is it

The 2027 exam is on Wednesday, May 5, 2027, in Session 2, and it takes 3 hours. That session starts at 12 p.m. local time in the lower 48 states, Hawaii and Washington, D.C. (11 a.m. in Alaska), and a school can begin it up to an hour later, so your coordinator is the one to ask about when to arrive.

One scheduling note worth having early: Physics C: Mechanics is on Monday, May 3, 2027, in Session 1, a different day and a different half of the day. If you are taking both, that is a Session 1 exam on Monday and a Session 2 exam on Wednesday, two days apart, not a double sitting.