Physics Equations for Grad School / Physics GRE Prep Motivation for asking question:
I am planning to take the GRE subject test for Physics. 
Question:
Can somebody please tell me what are the most important equations I should definitely know and understand completely going into this test and for entering first year Grad School for physics?
(schodinger equation, F = dp/dt, Maxwell Equations, what else?)
Follow up Question:
What are some miscellaneous equations that are also important to know? 
 A: The GRE physics exam is partitioned into at least 7 different subject areas, so there are no "singly important" formulae, I'm sorry to report.  The breakdown is roughly 20% allocated to E&M and Mechanics, and between 5-15% for Quantum, AMO, Relativity, Lab Methods, etc.  There's a wiki page with this breakdown, so this may be a good place to look for formulas.
I would say that a lot of this subject matter is encompassed in advanced undergraduate texts, so hitting a good comprehensive text is a good place to start.  Further, the GRE is multiple choice, so get good at eliminating answers that don't make sense for dimensional, scale reasons right off the bat, and consider the strategy of just knowing when not to answer since the grading scheme takes into account the total number of questions answered. 
There are various study guide and practice tests available at the ETS Website for free, so this would be a good help, and there is an entire forum available for consult on topics related to graduate school and physics at PhysicsGRE.com.
Good luck!!
A: Go to a library or a good college town bookstore, look for and browse through "University of Chicago Graduate Problems in Physics"  by Cronin, Greenberg & Telegdi.  Aim to be familiar with enough ideas and techniques to be able to answer at least half the questions.  
A: The phrasing of your question worries me. Learning physics doesn't have anything to do with memorizing equations. If you understand the meaning of an equation, you shouldn't have to memorize it.
A: If you are getting started, 70-80% of the GRE is based on freshman physics from any standard textbooks such as Halliday and Resnick, extended version (which means modern physics included). For this, all the equations you are asking about can be found in the summary that follows every chapter. Of course it goes without saying that memorizing the equations is completely useless unless you understand how they are used.
A: Woan's The Cambridge Handbook of Physics Formulas is very good for preparing for the GRE.
A: Daniel Beller of Brandeis has put together a nice and reasonably short pdf of the formulae you need to know as "Things to Know for the PHysics GRE". 
A: You can try the formula-and-concept review that I made when I was studying for it in 2005:
http://sjbyrnes.com/studysheet.pdf
(15 page PDF)
I'm especially proud of the mnemonics I came up with, like "In a diamagnet, the magnetic field dies" to remember which one is diamagnetic versus paramagnetic... Or S,P,D,F,G (the angular momentum quantum number labels) can be short for "Some Physicists are Destined to Flunk the GRE" :-P
A: This is by far the most helpful website I have seen.
There are videos for all major topics covered plus some comprehensive but concise notes.
There is also a remedial section if you have missed any of the core courses.
https://www.troy.edu/academics/colleges-schools/college-arts-sciences/departments/school-science-technology/chemistry-physics/physics/physics-gre.html
