The free response section is half of your AP Physics C: E&M score and the part most students underprepare for. There are four FRQs with named task types, each testing a distinct skill, for a total of 40 rubric points in 95 minutes. E&M is where the calculus in Physics C is heaviest: fields and potentials of continuous distributions are integrals, Gauss's and Ampere's laws are flux and line integrals, and RC, LR and LC circuits are differential equations. This page breaks down the format, what each task type wants from you, and the scoring patterns that show up year after year in the rubrics.
FRQs
4
One of each task type
Time
95 min
Roughly 24 min each
Rubric points
40
Split varies by year
Section weight
50%
Equal with MCQ
The four task types
FRQ Section II
The section is worth 40 rubric points across four questions. The point values below are the CED's suggested split, shown to give a sense of relative weight; the real values move a little from year to year.
01
Mathematical Routines
~10 pts · 20 to 25 min · Symbolic and numeric problem solving
Use physics principles to analyze a scenario and predict an outcome. In E&M this is usually a field or potential of a continuous distribution, a Gauss's-law or Ampere's-law derivation, or a circuit whose current or charge is a function of time. You derive symbolically, then evaluate.
Draw the Gaussian surface or Amperian loop and say why the symmetry lets you pull E or B out of the integral. That sentence is a rubric point; the algebra after it is worth less than students expect.
Write the integral with its limits and its dq or dℓ in terms of one variable before evaluating. The setup scores on its own.
Include units and a sign or a direction with every numerical answer. A magnitude with no direction on a field or force loses the point.
02
Translation Between Representations
~12 pts · 25 to 30 min · Connecting graphs, diagrams, and math
Move between field maps, equipotential diagrams, circuit diagrams, graphs of V(r), I(t) or Φ(t), and equations. You are given the situation in one form and asked to redraw it in another, derive an equation, sketch a graph, and then reconcile them or predict what changes.
Field lines start on positive charge, end on negative, never cross, and are denser where the field is stronger. Equipotentials cross them at right angles. Readers check all four.
Label every axis with a quantity and a unit, and mark the asymptotes and intercepts a circuit graph has (I0, ε/R, τ).
Match slopes and areas to the calculus: the slope of Φ against t is the emf, the area under I against t is the charge. The units must check out.
03
Experimental Design and Analysis
~10 pts · 25 to 30 min · Designing a procedure and analyzing data
Design a lab procedure to test a stated relationship, name what to measure with what equipment, then analyze data to draw a conclusion. E&M labs are usually a resistor, capacitor, coil or solenoid measured with a multimeter, an ammeter and voltmeter, or a Hall probe, and the analysis nearly always linearizes: plot the right pair so the slope is ρ, C, μ0n or L.
Name specific equipment and what it measures (voltmeter across the element, ammeter in series with it, a magnetic-field sensor on the axis of the coil).
State what you would vary, what you would hold constant, and what you would measure, and vary ONE thing.
Linearize when asked. "Plot ln(V) against t; the slope is −1/RC" is the kind of answer the rubric rewards, and it wants the slope's meaning stated, not just the plot.
04
Qualitative/Quantitative Translation
~8 pts · 15 to 20 min · Explanation backed by math
Explain a physical phenomenon in words, then back it up with a mathematical relationship. Lenz's law arguments, brightness comparisons when a switch closes, and "does the field inside change if the charge outside moves" live here. The paragraph is graded against a rubric that lists each scoring point individually.
Use claim, evidence, reasoning structure. State the claim, cite the law or equation, explain why it applies to this scenario.
Address the prompt directly. Restating a law without tying it to the scenario scores nothing.
If two scenarios are compared, the paragraph must reference both explicitly, and if a direction is asked for, the paragraph must name it.
Five FRQ scoring patterns that show up every year
Drawn from published College Board rubrics
Symmetry before substitution. Every Gauss's-law and Ampere's-law derivation awards a point for stating the symmetry that makes the field uniform over the surface or loop, and another for the correct enclosed charge or current. Students who write the final formula from memory skip both.
Direction is a separate skill from magnitude. Field, force and current directions earn their own points. A right-hand-rule answer with no stated rule, or a Lenz's-law answer that opposes the flux instead of its change, loses them.
"Justify your answer" means cite physics. An answer with no justification scores zero on those parts even if numerically correct. Name the principle (Kirchhoff's loop rule, Faraday's law, conservation of charge) and tie it to the scenario.
Linearization is testable. Roughly half of Experimental Design FRQs ask you to identify what to plot to get a straight line, and E&M's exponentials make ln plots the recurring case. Practice rewriting V(t) = V0e−t/RC as a line and saying what the slope means.
Sign conventions carry points. Potential difference across a resistor drops in the direction of current; the emf across an inductor opposes the change in current; potential energy of a charge is qV with the sign of q kept. Mixing these up is the most common single-point loss on Mathematical Routines questions.
Released FRQs and scoring guides
Official College Board materials
The College Board posts each year's FRQs along with scoring guidelines and sample student responses on AP Central. Work through at least the most recent three administrations. For pre-2025 FRQs, note that the exam was then 90 minutes with three FRQs and no calculator on multiple choice; the underlying physics is unchanged, so older problems remain strong practice even where the format differs.
Because AP Physics C: E&M is calculus-based, prioritize released problems that ask you to set up an integral or a differential equation, not just items that share a topic name with an algebra-based course.
Stop losing FRQ points to the same misconceptions
FRQ losses are rarely about not knowing the formula. They are almost always about a specific misconception: treating a field line as a path, reading V = 0 as E = 0, opposing the flux rather than its change, or applying Gauss's law where the symmetry does not hold. Diagnose which ones are costing you points.
Four. The AP Physics C: Electricity and Magnetism free response section has one of each named task type: Mathematical Routines, Translation Between Representations, Experimental Design and Analysis, and Qualitative/Quantitative Translation. Together they are worth 40 rubric points across 95 minutes.
How much is each FRQ worth?
The section totals 40 rubric points. The CED's suggested split is 10, 12, 10 and 8 points with suggested times of 20 to 25, 25 to 30, 25 to 30 and 15 to 20 minutes, but per-question values shift year to year. The FRQ section as a whole contributes 50 percent of your composite score.
How long should I spend on each FRQ?
The section is 95 minutes for four questions, so roughly 24 minutes each. Give the Translation and Experimental Design questions a little more and the Qualitative/Quantitative one a little less, which is what the CED's suggested times do.
Do I have to write paragraph-form responses?
The Qualitative/Quantitative Translation FRQ requires a written paragraph that follows a claim, evidence, reasoning structure. Other FRQs may include short justification prompts. Bullet points are acceptable for shorter justifications, but the paragraph response is graded as connected prose.
Do I need calculus on the FRQs?
Yes, and it is the part of the exam where E&M is most demanding. Expect to integrate over a charge or current distribution, evaluate a flux integral, write ΔV as an integral of E, or set up and solve the differential equation for an RC, LR or LC circuit. Showing the setup is usually its own scoring point.
Are recent AP Physics C: E&M FRQs released?
Yes. Each administration's FRQs and scoring guidelines are posted on AP Central. The 2025 and 2026 sets are the ones that reflect the current four-task-type, three-hour format and are the highest-fidelity practice you can do.
