What You Need to Know About the AP Physics Exam (page 3)
The AP Physics exam that you will take was first offered by the College Board in 1954. Since then, the number of students taking the test has grown rapidly. In 2009, more than 50,000 students took the AP Physics B exam, more than 25,000 students took at least one of the the AP Physics C exams, and those numbers go up every year.
Some Frequently Asked Questions About the AP Physics B & C Exams
Why Should I Take the AP Physics Exam?
Many of you take the AP Physics exam because you are seeking college credit. The majority of colleges and universities will award you some sort of credit for scoring a 4 or a 5. A small number of schools will even accept a 3 on the exam. This means you are one or two courses closer to graduation before you even start college!
Therefore, one compelling reason to take the AP exam is economic. How much does a college course cost, even at a relatively inexpensive school? You're talking several thousand dollars. If you can save those thousands of dollars by paying less than a hundred dollars now, why not do so?
Even if you do not score high enough to earn college credit, the fact that you elected to enroll in AP courses tells admission committees that you are a high achiever and serious about your education. In recent years, about 60% of students have scored a 3 or higher on their AP Physics B or C exam.
You'll hear a whole lot of misinformation about AP credit policies. Don't believe anything a friend (or even an adult) tells you; instead, find out for yourself. A good way to learn about the AP credit policy of the school you're interested in is to look it up on the College Board's official Web site, at http://apps.collegeboard.com/apcreditpolicy/ index.jsp. Even better, contact the registrar's office or the physics department chairman at the college directly.
What's the Difference Between Physics B and Physics C?
There are two AP Physics courses that you can take—Physics B and Physics C—and they differ in both the range of topics covered and the level at which those topics are tested. Here's the rundown.
As a survey course, Physics B covers a broad range of topics. This book's table of contents lists them all. This course is algebra-based—no calculus is necessary. In fact, the most difficult math you will encounter is solving two simultaneous algebraic equations, which is probably something you did in ninth grade.
The B course is ideal for ALL college-bound high school students. For those who intend to major in math or the heavy duty sciences, Physics B serves as a perfect introduction to college-level work. For those who want nothing to do with physics after high school, Physics B is a terrific terminal course—you get exposure to many facets of physics at a rigorous yet understandable level.
Most importantly, for those who aren't sure in which direction their college career may head, the B course can help you decide: "Do I like this stuff enough to keep studying it, or not?"
Although it is intended to be a second-year course, Physics B is often successfully taught as an intensive first-time introduction to physics.
This course is ONLY for those who have already taken a solid introductory physics course and are considering a career in math or science. Some schools teach Physics C as a follow-up to Physics B, but as long as you've had a rigorous introduction to the subject, that introduction does not have to be at the AP level.
Physics C is a course in two parts: (1) Newtonian Mechanics, and (2) Electricity and Magnetism. Of course, the B course covers these topics as well. However, the C course goes into greater depth and detail. The problems are more involved, and they demand a higher level of conceptual understanding. You can take either or both 90-minute parts of the Physics C exam.
The C course requires some calculus. Although much of the material can be handled without it, you should be taking a good calculus course concurrently.
What Is the Format of the Exam?
The following table summarizes the format of the AP Physics B and C exams.
Who Writes the AP Physics Exam?
Development of each AP exam is a multiyear effort that involves many education and testing professionals and students. At the heart of the effort is the AP Physics Development Committee, a group of college and high-school physics teachers who are typically asked to serve for three years. The committee and other physics teachers create a large pool of multiplechoice questions. With the help of the testing experts at Educational Testing Service (ETS), these questions are then pre-tested with college students for accuracy, appropriateness, clarity, and assurance that there is only one possible answer. The results of this pre-testing allow each question to be categorized by degree of difficulty. After several more months of development and refinement, Section I of the exam is ready to be administered.
The free-response questions that make up Section II go through a similar process of creation, modification, pre-testing, and final refinement so that the questions cover the necessary areas of material and are at an appropriate level of difficulty and clarity. The committee also makes a great effort to construct a free-response exam that will allow for clear and equitable grading by the AP readers.
At the conclusion of each AP reading and scoring of exams, the exam itself and the results are thoroughly evaluated by the committee and by ETS. In this way, the College Board can use the results to make suggestions for course development in high schools and to plan future exams.
What Topics Appear on the Exam?
The College Board, after consulting with physics teachers at all levels, develops a curriculum that covers material that college professors expect to cover in their first-year classes. Based on this outline of topics, the multiple-choice exams are written such that those topics are covered in proportion to their importance to the expected understanding of the student.
Confused? Suppose that faculty consultants agree that, say, atomic and nuclear physics is important to the physics curriculum, maybe to the tune of 10%. If 10% of the curriculum is devoted to atomic and nuclear physics, then you can expect roughly 10% of the exam will address atomic and nuclear physics. This includes both the multiple-choice and the free-response sections—so a topic that is not tested in the free-response section will have extra multiple-choice questions to make up the difference.
Below are the general outlines for the AP Physics curriculum and exams. Remember this is just a guide, and each year the exam differs slightly in the percentages.
What Types of Questions Are Asked on the Exam?
The multiple-choice questions tend to focus either on your understanding of concepts or on your mastery of equations and their meaning. Here's an example of a "concept" multiple-choice question.
The answer is B. Kirchoff 's junction rule states that whatever charge comes in must come out. If you don't remember Kirchoff 's junction rule, turn to Chapter 21, Circuits.
And here's an example of an "equation" multiple-choice question.
The answer is B. For this kind of question, you either remember the equation for the capacitance of a parallel plate capacitor,
or you don't. For help, turn to Chapter 6, Memorizing Equations in the Shower.
For the multiple-choice part of the exam, you are given a sheet that contains a bunch of physical constants (like the mass of a proton), SI units, and trigonometric values (like "tan 45° = 1"). All in all, this sheet is pretty useless—you'll probably only refer to it during the course of the test if you need to look up an obscure constant. That doesn't happen as often as you might think.
The free-response questions take 10–15 minutes apiece to answer, and they test both your understanding of concepts and your mastery of equations. Some of the free-response questions ask you to design or interpret the results of an experimental setup; others are more theoretical. Luckily, for this portion of the exam, in addition to the constant sheet you get with the multiple-choice questions, you will also get a sheet that contains every equation you will ever need.
We talk in much more detail about both the multiple-choice and the free-response sections of the test later, in Step 5, so don't worry if this is all a bit overwhelming now.
Who Grades My AP Physics Exam?
Every June, a group of physics teachers gathers for a week to assign grades to your hard work. Each of these "readers" spends a day or so getting trained on one question—and one question only. Because each reader becomes an expert on that question, and because each exam book is anonymous, this process provides a very consistent and unbiased scoring of that question.
During a typical day of grading, a random sample of each reader's scores is selected and crosschecked by other experienced "Table Leaders" to ensure that the consistency is maintained throughout the day and the week. Each reader's scores on a given question are also statistically analyzed, to make sure they are not giving scores that are significantly higher or lower than the mean scores given by other readers of that question. All measures are taken to maintain consistency and fairness for your benefit.
Will My Exam Remain Anonymous?
Absolutely. Even if your high-school teacher happens to randomly read your booklet, there is virtually no way he or she will know it is you. To the reader, each student is a number, and to the computer, each student is a bar code.
What About That Permission Box on the Back?
The College Board uses some exams to help train high-school teachers so that they can help the next generation of physics students to avoid common mistakes. If you check this box, you simply give permission to use your exam in this way. Even if you give permission, your anonymity is still maintained.
How Is My Multiple-Choice Section Scored?
The multiple-choice section of each physics exam is worth half of your final score. Your answer sheet is run through the computer, which adds up your correct responses and subtracts a fraction for each incorrect response. For every incorrect answer that you give, one-quarter of a point is deducted and the total is a raw score. This formula looks something like this:
- Section I Raw Score = Nright – 0.25Nwrong
If I Don't Know the Answer, Should I Guess?
One-fourth of a point is subtracted from your score for every question you answer incorrectly; however, no deduction is made for a question you don't answer at all. This deduction of one-fourth of a point for an incorrect response is called the "guessing penalty." If you don't have time to read the question or you've read it but can't eliminate any of the answer choices, the odds are that you'll neither help nor hurt your score. However, if you can eliminate one or more of the answer choices, the odds change and you are likely to improve your score by guessing among the remaining choices. So the strategy you should pursue is simple: Never guess wildly, but if you can eliminate at least one answer choice, you'll get your best score by guessing among the remaining choices.
How Is My Free-Response Section Scored?
Your performance on the free-response section is also worth half of your final score. This section of the Physics C exams each consist of three questions, worth 15 points each. The Physics B free-response section will consist of longer questions, worth 15 points, and slightly shorter questions, worth 10 points. Your score on the free-response section is simply the sum of your scores on each problem.
How Is My Final Grade Determined and What Does It Mean?
Each section counts 50% of the exam. The total composite score is thus a weighted sum of the multiple-choice and the free-response sections. In the end, when all of the numbers have been crunched, the Chief Faculty Consultant converts the range of composite scores to the 5-point scale of the AP grades. This conversion is not a true curve—it's not that there's some target percentage of 5s to give out. This means you're not competing against other test takers. Rather, the 5-point scale is adjusted each year to reflect the same standards as in previous years. The goal is that students who earn 5s this year are just as strong as those who earned 5s in 2000 or 2005.
The tables at the end of the practice exams in this book give you a rough example of a conversion, and as you complete the practice exams, you should use this to give yourself a hypothetical grade. Keep in mind that the conversion changes slightly every year to adjust for the difficulty of the questions—but, generally, it takes only about 65% of the available points to earn a 5.
Finally, you should receive your grade in early July.
How Do I Register and How Much Does It Cost?
If you are enrolled in AP Physics in your high school, your teacher will provide all of these details, but a quick summary here can't hurt. After all, you do not have to enroll in the AP course to register for and complete the AP exam. When in doubt, the best source of information is the College Board's Web site: www.collegeboard.com
The fee for taking the exams is $86 for each exam. (This means $86 for Physics B, and $86 each for Physics C Mechanics and for Physics C Electricity and Magnetism.) Students who demonstrate financial need may receive a $22 refund to help offset the cost of testing. In addition, for each fee-reduced exam, schools forgo their $8 rebate, so the final fee for these students is $56 per exam. Finally, many states offer exam subsidies to cover all or part of the cost. You can learn more about fee reductions and subsidies from the coordinator of your AP program, or by checking specific information on the official Web site: www.collegeboard.com.
I know that seems like a lot of money just for a test. But, you should think of this $86 as the biggest bargain you'll ever find. Why? Most colleges will give you a few credit hours for a good score. Do you think you can find a college that offers those credit hours for less than $86? Usually you're talking hundreds of dollars per credit hour! You're probably saving thousands of dollars by earning credits via AP.
There are also several optional fees that must be paid if you want your scores rushed to you or if you wish to receive multiple-grade reports. Don't worry about doing that unless your college demands it. (What, you think your scores are going to change if you don't find them out right away?)
The coordinator of the AP program at your school will inform you where and when you will take the exam. If you live in a small community, your exam may not be administered at your school, so be sure to get this information.