AP Physics C Exam Overview
The AP Physics Exam - C
Physics C has two exams: Physics C (Mechanics) and Physics C (Electricity and Magnetics). Both are
90 minutes long and cover one semester of an introductory college course with calculus intended for
students planning to major in a physical science or engineering.
See the Topic Outline for the percentages of each exam that are devoted to each major category.
Departures from these percentages in the free-response section in any given year are compensated
for in the multiple-choice sections so that the overall topic distribution for the entire examination is
achieved as closely as possible, although it may not be reached exactly.
About the Exam
Both Physics C exams are 90 minutes long and contain 45 minutes of multiple-choice questions and 45
minutes of free-response questions. You can use a scientific, programmable, or graphing calculator on
the free-response sections. Your exam packet will also include tables of commonly used physics
equations.
Section I: Multiple-Choice
The multiple-choice sections of both exams contain 35 questions and test the breadth of your
knowledge and understanding of the basic principles of physics.
Section II: Free-Response
The free-response sections of both exams contain three questions. You are expected to spend about
15 minutes answering each of these questions. Compared to the multiple-choice sections, the freeresponse sections emphasize the application of the basic principles of physics in greater depth in
solving more extended problems. Questions may ask students to:

Determine directions of vectors or paths of particles

Draw or interpret diagrams

Interpret or express physical relationships in graphical form

Account for observed phenomena

Interpret experimental data, including their limitations and uncertainties

Construct and use conceptual models and explain their limitations

Explain steps taken to arrive at a result or to predict future physical behavior

Manipulate equations that describe physical relationships

Obtain reasonable estimates
Solve problems that require the determination of physical quantities in either numerical or
symbolic form and that may require the application of single or multiple concepts

Laboratory-related questions may ask you to:
Design experiments, including identifying equipment needed and describing how it is to be
used; drawing diagrams or providing descriptions of experimental setups; or describing procedures to
be used, including controls and measurements to be taken

Analyze data, including displaying data in graphical or tabular form, fitting lines and curves to
data points in graphs, performing calculations with data, or making extrapolations and interpolations
from data

Analyze errors, including identifying sources of error and how they propagate, estimating
magnitude and direction of errors, determining significant digits, or identifying ways to reduce error

Communicate results, including drawing inferences and conclusions from experimental data,
suggesting ways to improve experiments, or proposing questions for further study

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AP Physics C Exam Overview
In grading the free-response sections, credit for answers depends on the quality of the solutions and
explanations shown, so be sure to show your work. If you make a mistake, you may cross it out or
erase it. Crossed-out work will not be graded, and credit may be lost for incorrect work that is not
crossed out. Some questions specifically ask you to justify your answer or to explain your reasoning.
In these cases, the graders are looking for some verbal or mathematical analysis that shows an
understanding of the concepts underlying physical phenomena as well as the ability to perform
mathematical manipulations necessary to generate the correct answer. This analysis may generally be
in the form of prose, equations, calculations, diagrams, or graphs.
As you complete the free-response section, remember:
It's important that you show your work in the space provided. If you need more space, clearly
indicate where you've continued your answer or you may lose credit. If you make a mistake, cross it
out or erase it; crossed-out work and work shown on the green insert will not be graded.

Credit for your free-response answers depends on the quality of the solutions and the
explanations given. Another reason to show all your work: You can receive partial credit. Correct
answers without supporting work may lose credit. This is especially true when you've been asked to
justify your answer because the graders will be looking for a verbal or mathematical analysis that
demonstrates how you arrived at your answer.


All final numerical answers should include appropriate units.
The best answers respond directly to the question asked. Pay special attention to directive
words and phrases when reading the questions. You should only provide the information required by
these terms:

"Justify" and "explain" call for an answer supported by prose, equations, calculations,
diagrams, or graphs. The prose or equations may refer to fundamental ideas or relations in physics,
such as Newton's laws, conservation of energy, Gauss' law, or Bernoulli's equation. In other cases, the
justification or explanation may take the form of analyzing the behavior of an equation for large or
small values of a variable in the equation.

"Calculate" means that you are expected to show work leading to a final answer, which may
be algebraic, but which is more often numerical.

"What is" and "determine" indicate that you don't need to show your work to obtain full credit.
But, showing work leading to answers is a good idea -- you can earn partial credit in the case of an
incorrect answer.

"Derive" is more specific and indicates that you need to begin your solution with one or more
fundamental equations, such as those given on the AP Physics Exam equation sheet. The final answer,
usually algebraic, is then obtained through the appropriate use of mathematics.

Conventions Used in the AP Physics C Exams
1.
Unless otherwise stated, the frame of reference of any problem is assumed to be inertial.
2.
The direction of any electric current is the direction of flow of positive charge (conventional
current).
3.
For any isolated electric charge, the electric potential is defined as zero at an infinite distance
from the charge.
The use of rulers or straight edges is permitted on the examinations to facilitate the sketching of
graphs or diagrams that might be required in the free-response sections.
Scoring the Exam
The multiple-choice and free-response sections each count toward 50 percent of the final grade.
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AP Physics C Exam Overview
Calculators
Calculators are not permitted on the multiple-choice section of the AP Physics Exams.
The purpose of the multiple-choice sections is to assess the breadth of students' knowledge and
understanding of the basic concepts of physics. The multiple-choice questions emphasize conceptual
understanding and qualitative applications. However, many physical definitions and principles are
quantitative by nature and can therefore be expressed as equations. The knowledge of these basic
definitions and principles, expressed as equations, is a part of the content of physics that should be
learned by physics students and will continue to be assessed in the multiple-choice sections. However,
any numeric calculations using these equations required in the multiple-choice sections will be kept
simple. Also, in some questions the answer choices differ by several orders of magnitude so that the
questions can be answered by estimation. Students should be encouraged to develop their skills not
only in estimating answers but also in recognizing answers that are physically unreasonable or
unlikely.
Calculators are allowed on the free-response section of the AP Physics Exams.
Calculators acceptable for AP Calculus are acceptable for AP Physics. In addition, non-graphing
scientific calculators without typewriter-style (QWERTY) keyboards may be used on the AP Physics
Exams (see the Calculator Policy section for either Calculus AB or Calculus BC). Students are not
required to erase their calculator memories before and after the examination. Calculators may not be
shared with other students.
The free-response sections emphasize solving in-depth problems where knowledge of which principles
to apply and how to apply them is the most important aspect of the solution to these problems.
Regardless of the type of calculator allowed, the examinations have been and will continue to be
designed and graded to minimize the necessity of doing lengthy calculations. Except for some
fundamental constants, most numerical values are selected so that calculations with them are simple
and can be done quickly. When free-response problems involve calculations, most of the points
awarded in the grading of the solution are given for setting up the solution correctly rather than for
actually carrying out the computation.
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