AP Physics C: E&M Practice
Three modes of free AP Physics C: Electricity and Magnetism practice, each built around a different question: where am I weak, can I fix one specific weakness, and can I put it all together under exam conditions. No account needed. Progress saves locally in your browser.
Mode 01
Diagnostic
Short topic-level assessments that pinpoint which specific misconceptions are costing you points. Each wrong answer is one of the 114 catalogued E&M errors, so a miss names the idea to repair rather than just the topic.
Start a diagnosticMode 02
Targeted drills
Once a diagnostic flags a misconception, an eight-item drill hits only that one idea with varied scenarios until you stop falling for it. That is usually where score gains come from.
Mode 03
Cumulative MCQ
Twenty-item unit exams that mirror AP Physics C: E&M format and difficulty, plus a whole-course cumulative across all six units. Best as a final check after lessons and drills, or as a baseline before a unit test.
Take a cumulativePractice by unit
Six units, AP Physics C: Electricity and Magnetism framework, numbered 8 to 13
- Unit 8Electric Charges, Fields, and Gauss's LawPractice ›
- Unit 9Electric PotentialPractice ›
- Unit 10Conductors and CapacitorsPractice ›
- Unit 11Electric CircuitsPractice ›
- Unit 12Magnetic Fields and ElectromagnetismPractice ›
- Unit 13Electromagnetic InductionPractice ›
Why targeting misconceptions works
Most AP Physics C: E&M problems are not hard because the integral is hard. They are hard because they are engineered to trip students into a specific wrong way of thinking. Field lines are not trajectories. Zero potential does not mean zero field, and zero field does not mean zero potential. Lenz's law opposes the change in flux, not the flux. If you do not hold the misconception, the problem is straightforward. If you do, no amount of additional practice will help unless that specific misconception is the one being addressed.
That is why Mistake Master is built around diagnose then drill rather than around problem volume. Working 200 practice problems with a misconception intact rebuilds the misconception 200 more times. Working eight drill problems that explicitly target the misconception, with feedback after each, rewires it.
Common questions
FAQ
Is Mistake Master free?
Yes. Every diagnostic, drill, and cumulative exam is free. No account required. Your progress saves in your browser using local storage.
How many practice problems are available?
About 1,200 items across the six units. Each of the 31 topics has a ten-item diagnostic, every one of the 114 catalogued misconceptions has an eight-item drill, and each unit has a twenty-item cumulative MCQ exam, plus a whole-course cumulative drawn from all six.
Where should I start?
If you have a unit test coming up, take that unit's cumulative MCQ cold to see where you stand. If you are early in the year or studying for the AP exam, run topic diagnostics for the units you have covered and let the results route you to drills.
Is this aligned to the College Board framework?
Yes. Items are anchored to the published AP Physics C: Electricity and Magnetism Course and Exam Description (units 8 to 13, essential knowledge statements), with internal misconception codes that map onto the most-cited findings in physics education research.
How long does a practice session take?
A topic diagnostic takes 10 to 15 minutes. A single drill takes 5 to 10 minutes. A full cumulative exam takes about 30 to 40 minutes.
Do I need Mechanics first?
The E&M course assumes the calculus and the force, energy and circular-motion ideas of Mechanics, and the College Board numbers its units 8 to 13 for that reason. You can practice E&M topics here without having used the Mechanics side of this site, but if a diagnostic keeps flagging energy or vector errors, the Mechanics units 3 and 4 diagnostics are the fastest way to find the underlying gap.