# Physics GRE

#### Quick** Overview**

- pGRE stands for Physics subject test for Graduate Record Examination (GRE), designed and taken by Educational Testing Service (ETS).
- The test consists of approximately
**100 questions with 5 choices**and you have**2 hours and 50 mins**to do it. You only have an average of**1.7 minutes per problem!**There are tricks that makes calculations much simpler which don’t require special knowledge. - Unlike general GRE and TOEFL,
**pGRE is a paper-based test.** - Physics GRE Test yields
**a total score on a 200 to 990 score scale, in 10-point increments**. - Questions can be answered on the basis of the first three years of undergraduate physics.
- The
**International System (SI) of units**is used predominantly in the test.**A table of information representing**various physical constants and a few conversion factors among SI units is presented in the test book. - He/She should be
**familiar with certain mathematical methods and their applications in physics**. Such mathematical methods include single and multivariate calculus, coordinate systems (rectangular, cylindrical and spherical), vector algebra and vector differential operators, Fourier series, partial differential equations, boundary value problems, matrices and determinants, and functions of complex variables. **Nothing is subtracted**from a score if you answer a question incorrectly or leave it blank. In the past, they used to penalize incorrect answers, but no longer.**No calculator**is allowed or given but only pencils.- The
**pGRE is offered 3 times per year**, in April, September, and October. Most people take pGRE either on Sept. or Oct. It’s up to you. - The
**cost of pGRE test is 150$**(See for more detail fees). - You can
**send four scores of your pGRE test for free.**You can add/delete/modify your score recipients after you register for that test. **For additional score report per recipient is 27$.**- You can view your scores online for free.
- There is also a
**fee reduction program**for GRE/PGRE which gives you the 50% discount per test. But, this is only for US citizens (See for eligibility description). - If you want to
**register for PGRE from Nepal**, you need to go to Nabil Bank (either at Teendhara, Durbar Marg branch or Chabahil branch, Kathmandu) and please make sure you have created an ETS account for GRE along with your personal information.

**Syllabus**

**CLASSICAL MECHANICS — 20%**

(such as kinematics, Newton’s laws, work and energy, oscillatory motion, rotational motion about a fixed axis, dynamics of systems of particles, central forces and celestial mechanics, three-dimensional particle dynamics, Lagrangian and Hamiltonian formalism, noninertial reference frames, elementary topics in fluid dynamics)**ELECTROMAGNETISM — 18%**

(such as electrostatics, currents and DC circuits, magnetic fields in free space, Lorentz force, induction, Maxwell’s equations and their applications, electromagnetic waves, AC circuits, magnetic and electric fields in matter)**OPTICS AND WAVE PHENOMENA — 9%**

(such as wave properties, superposition, interference, diffraction, geometrical optics, polarization, Doppler effect)**THERMODYNAMICS AND STATISTICAL MECHANICS — 10%**

(such as the laws of thermodynamics, thermodynamic processes, equations of state, ideal gases, kinetic theory, ensembles, statistical concepts and calculation of thermodynamic quantities, thermal expansion and heat transfer)**QUANTUM MECHANICS — 12%**

(such as fundamental concepts, solutions of the Schrödinger equation (including square wells, harmonic oscillators, and hydrogenic atoms), spin, angular momentum, wave function symmetry, elementary perturbation theory)**ATOMIC PHYSICS — 10%**

(such as properties of electrons, Bohr model, energy quantization, atomic structure, atomic spectra, selection rules, black-body radiation, x-rays, atoms in electric and magnetic fields)**SPECIAL RELATIVITY — 6%**

(such as introductory concepts, time dilation, length contraction, simultaneity, energy and momentum, four-vectors and Lorentz transformation, velocity addition)**LABORATORY METHODS — 6%**

(such as data and error analysis, electronics, instrumentation, radiation detection, counting statistics, interaction of charged particles with matter, lasers and optical interferometers, dimensional analysis, fundamental applications of probability and statistics)**SPECIALIZED TOPICS — 9%**

Nuclear and Particle physics (e.g., nuclear properties, radioactive decay, fission and fusion, reactions, fundamental properties of elementary particles), Condensed Matter (e.g., crystal structure, x-ray diffraction, thermal properties, electron theory of metals, semiconductors, superconductors), Miscellaneous (e.g., astrophysics, mathematical methods, computer applications)

**Download an Official Practice Book of PGRE.**

**Links**

- https://en.wikipedia.org/wiki/GRE_Physics_Test gives a good overview of the topics.
- https://www.ets.org/gre is an official webpage of PGRE.
- PhysicsGRE.com is a great independent site with lots of tips and advice on how to prepare for the exam. Also, a web forum for discussion of issues related to the GRE, and the grad school application process in general.
- The Ohio State University has a great physics GRE study site. Their site has all of the released tests.
- GREPhysics.net has detailed solutions to all of the physics GRE questions. A compilation of the 400 problems released by ETS prior to 2011, and student-contributed solutions.
- https://jaan.io/how-to-ace-the-gre-and-physics-gre/ gives an excellent advice to ace on PGRE preparation.
- https://thegradcafe.com is a place where you discuss the information related to Graduate studies.
- http://www.alexhunterlang.com/physics-gre gives some wonderful tips.
- https://sites.google.com/a/uw.edu/physicsgre/home is a great website from a study group at the Astronomy department of the University of Washington.
- http://great.cwru.edu Case Western Group provide the flashcards for PGRE. Download its Android app at http://www.phys.cwru.edu/flashcards/secr3t/
- https://www.aps.org/careers/guidance/webinars/gre-strategies.cfm : Webinar “Preparing for the Physics GRE: Strategies for Success”.
- http://www.physicsgreprep.com/Resources.pdf provides recommended textbooks.
- http://phdcomics.com gives fun while you get hang while preparing PGRE.
- https://www.ets.org/s/gre/pdf/gre_guide.pdf is an official guide about General and Subject GREs.
- https://www.ets.org/Media/Tests/GRE/pdf/gre_0809_factors_2006-07.pdf provides the factor that can affect performance in GRE.

**Books recommended**

- Cracking the GRE by Princeton Review, and its practice book is good for grasping techniques to solve the problem at a good pace.
- Conquering the Physics GRE also gives important strategies.
- Kirkby’s Physics: A Student Companion is a nice all-around summary of a wide range of physics topics. It’s geared toward students studying for exams, so it is concise and more distilled than the subject-specific books.

#### Presentation slides

- Acing the Physics GRE by APS.
- Preparing for the Physics GRE: Strategies for Success by APS.
- Preparation for Physics GRE: Day 1, Introduction and strategies.
- Preparation for Physics GRE: Day 2, Atomic Physics
- Preparation for Physics GRE: Day 3, Statistical Mechanics, Black Body radiation and Thermodynamics
- Preparation for Physics GRE: Day 4, Circuits and Optics
- Preparation for Physics GRE: Day 5, Wave interference and Difficult problems

**Tips**

- Be completely familiar with the format of the test, including the answer “bubble answer sheets”, etc. Because you don’t want to waste time finding your way around the test booklet on test day.
- The questions are ordered randomly (in terms of topic). But some questions are grouped together.
- Some questions can be most quickly answered by looking at dimensional arguments, order-of-magnitude estimates or limiting behaviors. This tricks will really help you.
- There are blank pages for calculations. i.e. SCRATCH WORK. Use this as much as needed.
- A good strategy is to make a first pass answering those questions you are confident about and returning for subsequent questions on a second (or third) pass. Because all questions carry equal weight.
- Don’t wait until the very end to fill in your answers on the answer sheet.
- Speed is essential. If you had five or 10 minutes to solve the questions on the physics GRE, anyone with a physics background could do it, but you need to answer most of the questions within a minute and a half. Try to eliminate solutions before doing calculations. Usually, you’ll only have 2 or 3 sensible answers left, and only a partial calculation will be necessary to determine which is correct.
- Do not spend more than about 4 minutes on any one question.
- Memorize equations sparingly, but as necessary.
- Look for short-cuts to the answer. Can you eliminate choices using units? Conservation laws? Unreasonable values?
- Make a set of flashcards, or email this group at Case Western.
- Keep it in perspective. You have to take this test to apply for grad school and it will make an impact on the school you attend, but it really is a poor indicator of your future career in research.
- Stay calm during the exam. It is very difficult and all the other students think it is difficult too.
- Undergraduate textbooks and course material probably the best preparation. But, don’t spend too much time with books (other than to review things you’re unsure of, or to help compile your own review summaries).
- If you’re wondering why books by Griffiths show up so often, it’s likely because he was on the question-writing committee for the Physics GRE exam several years ago. Anecdotally, we know that questions are recycled very often (which is why so few exams have been released), so it’s likely that many of the questions you’ll see on your exam were written by Griffiths or consciously modeled after his book.
- Obtain copies of all past Physics GRE tests.
- You may find it useful to compile your own summaries of material.
- Practice … Practice … Practice! Remember! As Vince Lombardi said, “Practice does not make perfect. Only perfect practice makes perfect.”

#### Tricks

**Always Guess**: If you can eliminate at least one answer then, guess it.**Order of Magnitude**: Your arithmetic does not need to be exact so, save time by avoiding decimal larger than 1 or 2 (means round off the numbers).**Dimensional Analysis**: You can eliminate many possible answers because they have incorrect dimensions which save a lot of time. Mass, length and time are the most commonly used three fundamental units. Everything in classical mechanics can be expressed as products of powers of these!**Taking Limits**: Check the given five choice answers to see if they make sense within certain limits.**5 magic numbers**: You need to memorize the below numbers. But, everything else should be given on formula sheet or in the exam questions themselves.

- 13.6 eV – Hydrogen atom binding energy
- 511 keV – Mass of the electron (units of c^2)
- 1.22 – Coefficient in Rayleigh criterion
- 2.7 K – Temperature of the cosmic microwave background
- 3 * 10^(-3) m.K – Wien’s law coefficient

**PGRE past test Questions **

I will highly recommend http://grephysics.net/ans/ for the past solutions of the year 2008, 2001, 1996, 1992, and 1986 practice test. But, it is good to see the below solutions to get some tricks. I strongly suggest to try one of these (maybe 2001 or 2008) under “test-taking conditions” to give you a feel for the test, and also to show your strong and weaker areas.

- GR1777(no online solutions)(2017)
- GR0877 (online solutions)(2008)
- GR0177 (online solutions)(2001)
- GR9677 (online solutions)(1996)
- GR9277 (online solutions)(1992)
- GR8677 (online solutions)(1986)

#### My own PGRE note

I have seen that there are no any materials written by a Nepali Student for Physics GRE test. So, I have taken an effort to share all the important guidelines that I will learn during my learning period (08 Sept to Oct 26, 2018) for my own PGRE test. This means I have planned to write this test on Oct 27. To those who are reading my note, BEST OF LUCK!

– Damodar Rajbhandari (Get my note at “Notes for the Physics GRE to Ace“)