Sanha Cheong / education.enthusiast

Physics GRE

GRE in Physics Graduate Admissions

The GRE stands for the Graduate Record Examination and is a standardized test used for admissions to graduate schools and business schools. Just like the SAT, there are the General and the Subject Tests.

The General GRE measures basic English abilities (critical reading & analytical writing) and quantitative skills. For physics major students, the quantitative section should be pretty easy, though one might need some practice to familiarize oneself with the test format. If a student's undergraduate degree is from an institution whose primary language of instruction is English, the English abilities are usually not a huge concern in the admissions process for Physics graduate programs in US. (It is much more important for an international applicant from a non-English institution, though it is still not the major deciding factor.)

What does really bug physics students when it comes to graduate admissions to US programs is the Physics GRE (PGRE). The PGRE, as are a lot of standardized tests, is a bad measure of one's understanding of physics or one's ability to succeed in grad school. However, it is unfortunately a non-trivial factor in the admissions for Physics graduate programs in US. A physics department chair at one of the top programs in US once told me, "It (PGRE) doesn't measure what we want to measure, but it measures something." People are becoming more and more aware of how ineffective it is, but, as of now, it is another bump that students aiming for admissions into good Physics PhD programs need to get through.

GRE Subject Tests are only offered three times a year: in April, September, and October. Hence, it is typical for physics major seniors to take the exam and September and October. Though difficult, it is very helpful if one can be done with the PGRE in the April of their junior year; senior fall is already extremely busy with applications, and having one less thing to worry about is huge.

If you need help preparing for the PGRE, here are some tips and a recommended plan with study materials. Hope this page helps and wish you good luck! There are other helpful pages as well: check out the PGRE help pages at the Stanford SPS or the UW Astronomy Department.

Basic Info & Tips

The PGRE consists of 100 multiple-choice (5 options) problems in 170 minutes, with material taken from practically all possible undergraduate physics topics.

The raw score is calculated as "# of correct answers - # of incorrect answers entered / 4" and then re-scaled to a score out of 990.

This is no longer true! You no longer lose points for guessing incorrectly. The raw score (# of correct answers) is re-scaled to a score between 200 and 990 with 10-point increments.

Beginning in the 2017–18 testing year (July 1–June 30), your raw score will be determined by the number of questions you answer correctly. Questions you answer incorrectly or for which you mark no answer or more than one answer are counted as incorrect. Nothing is subtracted from a score if you answer a question incorrectly.

-FAQ about the GRE Subject Tests
So, even if you have absolutely no idea about a problem, you should ALWAYS take a guess.

Okay, so that is the basic structure of the exam, but what does it imply?

First, you NEED to be fast. You cannot and should not do all the detailed calculations; dimensional analysis and other intuitions can almost always eliminate a few answers without any calculation. Don't forget to:

The other, perhaps obvious, point to note is that it is difficult to recall ALL undergrad materials. It will probably require some conceptual reviews, no matter how good you have been throughout your undergrad core courses. (If not, fantastic! You need not worry.) I strongly recommend spending some time on conceptual review of all topics you have learned so far, before jumping into past exams.

At the same time, it is unrealistic to learn all materials that can possibly be on the exam. However, getting a perfect 990 scaled score does not require a perfect raw score. The scale varies from an exam to another, but a raw score of 80 or so can still correspond to a 990 scaled score. So, be wise, and don't obsess yourself with perfection. Also, in the topics that you are not so familiar with, the techniques above can really help.

Study Materials

Here are some conceptual review notes that my friend Greg Loges (who is now a grad student at UW Madison) and I wrote when we ran a PGRE tutoring program at University of Rochester. (Really, Greg wrote most of it.) The numbers in the parentheses are the relative weights of the topics in the PGRE.

Classical Mechanics (20%) Electromagnetism (18%)
Optics & Waves (9%) Thermo. & Stat. Mech. (10%)
Quantum Mechanics (12%) Atomic Physics (10%)
Special Relativity (6%) Laboratory Methods (6%)
Special Topics (9%) Short Overall Summary

In addition, though I did not use it myself, I have heard that the book "Conquering the Physics GRE" is also very helpful.

Also, here are 5 past exams, including respective answer sheets and the score conversion tables at the end.

1986 Exam 1992 Exam 1996 Exam 2001 Exam 2008 Exam

Recommended Plan

First, spend some time on conceptual review of all the topics using the notes above, the book, or other study resources you like. (Of course, the exact time needed will vary.) Again, it is unrealistic to know all the details of all topics, but you should at least have a look. Since there are only 5 past exams available (as far as I know), I do not recommend starting with a real exam; save them for later, when you feel at least somewhat ready. If you are preparing for the September and/or October exam, take the first few weeks of summer break to really review the concepts.

Once you have studied the materials decently, start taking the past exams. After each practice exam, keep track of which problems (from which topic) you missed, thoroughly review the corresponding material, and make sure you don't miss similar problems in the next one. I also encourage that you take each practice like an actual exam: print out the exam and take it under a quiet & timed environment. It is important to get used to the test-taking environment.

Ideally, the practices should begin by 5 weeks before your actual exam. Then, you have at least a week to correct yourself and review the parts you feel less confident about. It does not matter too much which exams you try first, but I recommend leaving 1996 and 2008 exams as the last two.