GRE physics test secrets study guide: your key to exam success

136 Pages·2010·0.911 MB·English

by  Mometrix Media LLC

ProductID: GREPhysics

GRE Physics
Test Secrets
Study Guide
Your Key to Exam Success

GRE Subject Exam Review for the
Graduate Record Examination
Dear Future Exam Success Story:

Congratulations on your purchase of our study guide. Our goal in writing our study guide
was to cover the content on the test, as well as provide insight into typical test taking
mistakes and how to overcome them.

Standardized tests are a key component of being successful, which only increases the
importance of doing well in the high-pressure high-stakes environment of test day. How
well you do on this test will have a significant impact on your future- and we have the
research and practical advice to help you execute on test day.

The product you’re reading now is designed to exploit weaknesses in the test itself, and help
you avoid the most common errors test takers frequently make.

How to use this study guide

We don’t want to waste your time. Our study guide is fast-paced and fluff-free. We suggest
going through it a number of times, as repetition is an important part of learning new
information and concepts.

First, read through the study guide completely to get a feel for the content and organization.
Read the general success strategies first, and then proceed to the content sections. Each tip
has been carefully selected for its effectiveness.

Second, read through the study guide again, and take notes in the margins and highlight
those sections where you may have a particular weakness.

Finally, bring the manual with you on test day and study it before the exam begins.

Your success is our success

We would be delighted to hear about your success. Send us an email and tell us your story.
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Mometrix Test Preparation Team

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TABLE OF CONTENTS
Secret Key #1 - Time is Your Greatest Enemy .............................................................................................. 4
Pace Yourself ......................................................................................................................................................... 4
Secret Key #2 - Guessing is not Guesswork ................................................................................................... 4
Monkeys Take the Test ..................................................................................................................................... 4
$5 Challenge .......................................................................................................................................................... 5
Secret Key #3 - Practice Smarter, Not Harder .............................................................................................. 5
Success Strategy ................................................................................................................................................... 6
Secret Key #4 - Prepare, Don’t Procrastinate ............................................................................................... 6
Secret Key #5 - Test Yourself ............................................................................................................................... 6
General Strategies .................................................................................................................................................... 7
Top 20 Test Taking Tips ..................................................................................................................................... 12
Classical Mechanics ............................................................................................................................................... 13
Electromagnetism ................................................................................................................................................. 29
Optics and Wave Phenomena ........................................................................................................................... 39
Thermodynamics and Statistical Mechanics .............................................................................................. 46
Quantum Mechanics, Atomic Physics, and Special Relativity .............................................................. 51
Laboratory Methods ............................................................................................................................................. 61
Practice Test ............................................................................................................................................................ 72
Answer Key ...................................................................................................................................................... 101
Special Report: What Your Test Score Will Tell You About Your IQ ............................................. 121
Special Report: What is Test Anxiety and How to Overcome It? .................................................... 123
Lack of Preparation ...................................................................................................................................... 123
Physical Signals .............................................................................................................................................. 124
Nervousness .................................................................................................................................................... 124
Study Steps ....................................................................................................................................................... 126
Helpful Techniques ....................................................................................................................................... 127
Special Report: Retaking the Test: What Are Your Chances at Improving Your Score? ....... 132
Special Report: Additional Bonus Material .............................................................................................. 134
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Secret Key #1 - Time is errors affect the score more than mastery
of material.
Your Greatest Enemy
Secret Key #2 -
Pace Yourself
Guessing is not
Wear a watch. At the beginning of the
Guesswork
test, check the time (or start a
chronometer on your watch to count the
minutes), and check the time after every

few questions to make sure you are “on
You probably know that guessing is a
schedule.”
good idea - unlike other standardized

tests, there is no penalty for getting a
If you are forced to speed up, do it
wrong answer. Even if you have no idea
efficiently. Usually one or more answer
about a question, you still have a 20-25%
choices can be eliminated without too
chance of getting it right.
much difficulty. Above all, don’t panic.

Don’t speed up and just begin guessing at
Most test takers do not understand the
random choices. By pacing yourself, and
impact that proper guessing can have on
continually monitoring your progress
their score. Unless you score extremely
against your watch, you will always know
high, guessing will significantly contribute
exactly how far ahead or behind you are
to your final score.
with your available time. If you find that

you are one minute behind on the test,
Monkeys Take the Test
don’t skip one question without spending

any time on it, just to catch back up. Take
What most test takers don’t realize is that
15 fewer seconds on the next four
to insure that 20-25% chance, you have to
questions, and after four questions you'll
guess randomly. If you put 20 monkeys in
have caught back up. Once you catch back
a room to take this test, assuming they
up, you can continue working each
answered once per question and behaved
problem at your normal pace.
themselves, on average they would get

20-25% of the questions correct. Put 20
Furthermore, don’t dwell on the problems
test takers in the room, and the average
that you were rushed on. If a problem
will be much lower among guessed
was taking up too much time and you
questions. Why?
made a hurried guess, it must be difficult.

The difficult questions are the ones you
1. The test writers intentionally write
are most likely to miss anyway, so it isn’t
deceptive answer choices that
a big loss. It is better to end with more
“look” right. A test taker has no
time than you need than to run out of
idea about a question, so picks the
time.
“best looking” answer, which is

often wrong. The monkey has no
Lastly, sometimes it is beneficial to slow
idea what looks good and what
down if you are constantly getting ahead
doesn’t, so will consistently be
of time. You are always more likely to
lucky about 20-25% of the time.
catch a careless mistake by working more

slowly than quickly, and among very high-
2. Test takers will eliminate answer
scoring test takers (those who are likely
choices from the guessing pool
to have lots of time left over), careless
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based on a hunch or intuition. all the answer choices, you are
Simple but correct answers often GUARANTEED to have a shot at the right
get excluded, leaving a 0% chance answer.
of being correct. The monkey has
no clue, and often gets lucky with That’s why the $5 test is so valuable- if
the best choice. you give up the advantage and safety of a
pure guess, it had better be worth the
This is why the process of elimination risk.
endorsed by most test courses is flawed
and detrimental to your performance- What we still haven’t covered is how to be
test takers don’t guess, they make an sure that whatever guess you make is
ignorant stab in the dark that is usually truly random. Here’s the easiest way:
worse than random.
Always pick the first answer choice among
$5 Challenge those remaining.

Such a technique means that you have
Let me introduce one of the most valuable
decided, before you see a single test
ideas of this course- the $5 challenge:
question, exactly how you are going to

guess- and since the order of choices tells
You only mark your “best guess” if you are
you nothing about which one is correct,
willing to bet $5 on it.
this guessing technique is perfectly
You only eliminate choices from guessing if
random.
you are willing to bet $5 on it.

This section is not meant to scare you
Why $5? Five dollars is an amount of
away from making educated guesses or
money that is small yet not insignificant,
eliminating choices- you just need to
and can really add up fast (20 questions
define when a choice is worth eliminating.
could cost you $100). Likewise, each
The $5 test, along with a pre-defined
answer choice on one question of the test
random guessing strategy, is the best way
will have a small impact on your overall
to make sure you reap all of the benefits
score, but it can really add up to a lot of
of guessing.
points in the end.

The process of elimination IS valuable.
Secret Key #3 - Practice
The following shows your chance of
guessing it right:
Smarter, Not Harder

If you eliminate Chance of getting
wrong answer it correct:
choices until only Many test takers delay the test
this many remain: preparation process because they dread
1 100% the awful amounts of practice time they
2 50% think necessary to succeed on the test.
3 33% We have refined an effective method that
will take you only a fraction of the time.
However, if you accidentally eliminate the There are a number of “obstacles” in your
right answer or go on a hunch for an way to succeed. Among these are
incorrect answer, your chances drop answering questions, finishing in time,
dramatically: to 0%. By guessing among and mastering test-taking strategies. All
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must be executed on the day of the test at preparedness you have, and, despite the
peak performance, or your score will test writers' claims to the contrary, some
suffer. The test is a mental marathon that tests WILL be easier for you than others.
has a large impact on your future.
Since your future depends so much on
Just like a marathon runner, it is your score, you should maximize your
important to work your way up to the full chances of success. In order to maximize
challenge. So first you just worry about the likelihood of success, you’ve got to
questions, and then time, and finally prepare in advance. This means taking
strategy: practice tests and spending time learning
the information and test taking strategies
Success Strategy you will need to succeed.

Never take the test as a “practice” test,
1. Find a good source for practice
expecting that you can just take it again if
tests.
you need to. Feel free to take sample
2. If you are willing to make a larger
tests on your own, but when you go to
time investment, consider using
take the official test, be prepared, be
more than one study guide- often
focused, and do your best the first time!
the different approaches of

multiple authors will help you
“get” difficult concepts.
Secret Key #5 - Test
3. Take a practice test with no time
constraints, with all study helps
Yourself
“open book.” Take your time with
questions and focus on applying
strategies.
4. Take a practice test with time Everyone knows that time is money.
constraints, with all guides "open There is no need to spend too much of
book." your time or too little of your time
5. Take a final practice test with no preparing for the test. You should only
open material and time limits spend as much of your precious time
preparing as is necessary for you to get
If you have time to take more practice the score you need.
tests, just repeat step 5. By gradually
exposing yourself to the full rigors of the Once you have taken a practice test under
test environment, you will condition your real conditions of time constraints, then
mind to the stress of test day and you will know if you are ready for the test
maximize your success. or not.
If you have scored extremely high the first
time that you take the practice test, then
Secret Key #4 - Prepare, there is not much point in spending
countless hours studying. You are
Don’t Procrastinate
already there.

Benchmark your abilities by retaking

practice tests and seeing how much you
Let me state an obvious fact: if you take
have improved. Once you score high
the test three times, you will get three
enough to guarantee success, then you
different scores. This is due to the way
are ready.
you feel on test day, the level of
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Answer the Question
If you have scored well below where you It may seem obvious to only pick answer
need, then knuckle down and begin choices that answer the question, but the
studying in earnest. Check your test writers can create some excellent
improvement regularly through the use of answer choices that are wrong. Don’t
practice tests under real conditions. pick an answer just because it sounds
Above all, don’t worry, panic, or give up. right, or you believe it to be true. It MUST
The key is perseverance! answer the question. Once you’ve made
your selection, always go back and check
Then, when you go to take the test, it against the question and make sure that
remain confident and remember how well you didn’t misread the question, and the
you did on the practice tests. If you can answer choice does answer the question
score high enough on a practice test, then posed.
you can do the same on the real thing.
Benchmark
After you read the first answer choice,
General Strategies decide if you think it sounds correct or
not. If it doesn’t, move on to the next
answer choice. If it does, mentally mark

that answer choice. This doesn’t mean
The most important thing you can do is to
that you’ve definitely selected it as your
ignore your fears and jump into the test
answer choice, it just means that it’s the
immediately- do not be overwhelmed by
best you’ve seen thus far. Go ahead and
any strange-sounding terms. You have to
read the next choice. If the next choice is
jump into the test like jumping into a
worse than the one you’ve already
pool- all at once is the easiest way.
selected, keep going to the next answer
choice. If the next choice is better than
Make Predictions
the choice you’ve already selected,
As you read and understand the question,
mentally mark the new answer choice as
try to guess what the answer will be.
your best guess.
Remember that several of the answer

choices are wrong, and once you begin
The first answer choice that you select
reading them, your mind will immediately
becomes your standard. Every other
become cluttered with answer choices
answer choice must be benchmarked
designed to throw you off. Your mind is
against that standard. That choice is
typically the most focused immediately
correct until proven otherwise by another
after you have read the question and
answer choice beating it out. Once you’ve
digested its contents. If you can, try to
decided that no other answer choice
predict what the correct answer will be.
seems as good, do one final check to
You may be surprised at what you can
ensure that your answer choice answers
predict.
the question posed.

Quickly scan the choices and see if your
Valid Information
prediction is in the listed answer choices.
Don’t discount any of the information
If it is, then you can be quite confident
provided in the question. Every piece of
that you have the right answer. It still
information may be necessary to
won’t hurt to check the other answer
determine the correct answer. None of
choices, but most of the time, you’ve got
the information in the question is there to
it!
throw you off (while the answer choices
will certainly have information to throw
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you off). If two seemingly unrelated recognize it. On difficult questions, you
topics are discussed, don’t ignore either. may not recognize a number of words in
You can be confident there is a the answer choices. The test writers
relationship, or it wouldn’t be included in don’t put “make-believe” words on the
the question, and you are probably going test; so don’t think that just because you
to have to determine what is that only recognize all the words in one
relationship to find the answer. answer choice means that answer choice
must be correct. If you only recognize
Avoid “Fact Traps” words in one answer choice, then focus
Don’t get distracted by a choice that is on that one. Is it correct? Try your best
factually true. Your search is for the to determine if it is correct. If it is, that is
answer that answers the question. Stay great, but if it doesn’t, eliminate it. Each
focused and don’t fall for an answer that word and answer choice you eliminate
is true but incorrect. Always go back to increases your chances of getting the
the question and make sure you’re question correct, even if you then have to
choosing an answer that actually answers guess among the unfamiliar choices.
the question and is not just a true
statement. An answer can be factually Eliminate Answers
correct, but it MUST answer the question Eliminate choices as soon as you realize
asked. Additionally, two answers can they are wrong. But be careful! Make
both be seemingly correct, so be sure to sure you consider all of the possible
read all of the answer choices, and make answer choices. Just because one appears
sure that you get the one that BEST right, doesn’t mean that the next one
answers the question. won’t be even better! The test writers
will usually put more than one good
Milk the Question answer choice for every question, so read
Some of the questions may throw you all of them. Don’t worry if you are stuck
completely off. They might deal with a between two that seem right. By getting
subject you have not been exposed to, or down to just two remaining possible
one that you haven’t reviewed in years. choices, your odds are now 50/50.
While your lack of knowledge about the Rather than wasting too much time, play
subject will be a hindrance, the question the odds. You are guessing, but guessing
itself can give you many clues that will wisely, because you’ve been able to knock
help you find the correct answer. Read out some of the answer choices that you
the question carefully and look for clues. know are wrong. If you are eliminating
Watch particularly for adjectives and choices and realize that the last answer
nouns describing difficult terms or words choice you are left with is also obviously
that you don’t recognize. Regardless of if wrong, don’t panic. Start over and
you completely understand a word or not, consider each choice again. There may
replacing it with a synonym either easily be something that you missed the
provided or one you more familiar with first time and will realize on the second
may help you to understand what the pass.
questions are asking. Rather than
wracking your mind about specific Tough Questions
detailed information concerning a If you are stumped on a problem or it
difficult term or word, try to use mental appears too hard or too difficult, don’t
substitutes that are easier to understand. waste time. Move on! Remember though,
if you can quickly check for obviously
The Trap of Familiarity incorrect answer choices, your chances of
Don’t just choose a word because you guessing correctly are greatly improved.
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Before you completely give up, at least try and you have to figure things out. Use
to knock out a couple of possible answers. your common sense to interpret anything
Eliminate what you can and then guess at that isn’t clear.
the remaining answer choices before
moving on. Prefixes
If you're having trouble with a word in
Brainstorm the question or answer choices, try
If you get stuck on a difficult question, dissecting it. Take advantage of every
spend a few seconds quickly clue that the word might include. Prefixes
brainstorming. Run through the complete and suffixes can be a huge help. Usually
list of possible answer choices. Look at they allow you to determine a basic
each choice and ask yourself, "Could this meaning. Pre- means before, post- means
answer the question satisfactorily?" Go after, pro - is positive, de- is negative.
through each answer choice and consider From these prefixes and suffixes, you can
it independently of the other. By get an idea of the general meaning of the
systematically going through all word and try to put it into context.
possibilities, you may find something that Beware though of any traps. Just because
you would otherwise overlook. con is the opposite of pro, doesn’t
Remember that when you get stuck, it’s necessarily mean congress is the opposite
important to try to keep moving. of progress!
Read Carefully Hedge Phrases
Understand the problem. Read the Watch out for critical “hedge” phrases,
question and answer choices carefully. such as likely, may, can, will often,
Don’t miss the question because you sometimes, often, almost, mostly, usually,
misread the terms. You have plenty of generally, rarely, sometimes. Question
time to read each question thoroughly writers insert these hedge phrases to
and make sure you understand what is cover every possibility. Often an answer
being asked. Yet a happy medium must choice will be wrong simply because it
be attained, so don’t waste too much time. leaves no room for exception. Avoid
You must read carefully, but efficiently. answer choices that have definitive words
like “exactly,” and “always”.
Face Value
When in doubt, use common sense. Switchback Words
Always accept the situation in the Stay alert for “switchbacks”. These are
problem at face value. Don’t read too the words and phrases frequently used to
much into it. These problems will not alert you to shifts in thought. The most
require you to make huge leaps of logic. common switchback word is “but”.
The test writers aren’t trying to throw Others include although, however,
you off with a cheap trick. If you have to nevertheless, on the other hand, even
go beyond creativity and make a leap of though, while, in spite of, despite,
logic in order to have an answer choice regardless of.
answer the question, then you should
look at the other answer choices. Don’t New Information
overcomplicate the problem by creating Correct answer choices will rarely have
theoretical relationships or explanations completely new information included.
that will warp time or space. These are Answer choices typically are
normal problems rooted in reality. It’s straightforward reflections of the
just that the applicable relationship or material asked about and will directly
explanation may not be readily apparent relate to the question. If a new piece of
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information is included in an answer you would like. Calm down and maintain
choice that doesn't even seem to relate to the pace that you have set for yourself. As
the topic being asked about, then that long as you are on track by monitoring
answer choice is likely incorrect. All of your pace, you are guaranteed to have
the information needed to answer the enough time for yourself. When you get
question is usually provided for you, and to the last few minutes of the test, it may
so you should not have to make guesses seem like you won’t have enough time
that are unsupported or choose answer left, but if you only have as many
choices that require unknown questions as you should have left at that
information that cannot be reasoned on point, then you’re right on track!
its own.
Answer Selection
Time Management The best way to pick an answer choice is
On technical questions, don’t get lost on to eliminate all of those that are wrong,
the technical terms. Don’t spend too until only one is left and confirm that is
much time on any one question. If you the correct answer. Sometimes though,
don’t know what a term means, then since an answer choice may immediately look
you don’t have a dictionary, odds are you right. Be careful! Take a second to make
aren’t going to get much further. You sure that the other choices are not equally
should immediately recognize terms as obvious. Don’t make a hasty mistake.
whether or not you know them. If you There are only two times that you should
don’t, work with the other clues that you stop before checking other answers. First
have, the other answer choices and terms is when you are positive that the answer
provided, but don’t waste too much time choice you have selected is correct.
trying to figure out a difficult term. Second is when time is almost out and
you have to make a quick guess!
Contextual Clues
Look for contextual clues. An answer can Check Your Work
be right but not correct. The contextual Since you will probably not know every
clues will help you find the answer that is term listed and the answer to every
most right and is correct. Understand the question, it is important that you get
context in which a phrase or statement is credit for the ones that you do know.
made. This will help you make important Don’t miss any questions through careless
distinctions. mistakes. If at all possible, try to take a
second to look back over your answer
Don’t Panic selection and make sure you’ve selected
Panicking will not answer any questions the correct answer choice and haven’t
for you. Therefore, it isn’t helpful. When made a costly careless mistake (such as
you first see the question, if your mind marking an answer choice that you didn’t
goes blank, take a deep breath. Force mean to mark). This quick double check
yourself to mechanically go through the should more than pay for itself in caught
steps of solving the problem and using the mistakes for the time it costs.
strategies you've learned.
Beware of Directly Quoted Answers
Pace Yourself Sometimes an answer choice will repeat
Don’t get clock fever. It’s easy to be word for word a portion of the question
overwhelmed when you’re looking at a or reference section. However, beware of
page full of questions, your mind is full of such exact duplication – it may be a trap!
random thoughts and feeling confused, More than likely, the correct choice will
and the clock is ticking down faster than paraphrase or summarize a point, rather
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