Exam 1

EDIT: I probably cannot stress enough that I mean this week.

Just under half of you have scheduled your oral exam so far. If you haven't requested a time yet, you should do it soon ... Here are the times left:

Wed: 2:30-4pm, 5-6:30ish pm
Thurs: pretty well tied up in an all-day meeting.
Fri: 10-10:45, 12:30-1:45, 4-5, 5:30-6, after 6:30 if you really want to

It will not take more than 15-20min for the oral exam. You can use your book for reference (though if you thumb through it too long I may look askance at you). The topics are, by section in the book,

22.2 Electric fields
22.4-7 fields of various charge distributions
22.9 dipoles in electric fields
23.4 Gauss' law
23.7-9 Gauss in various situations

Nothing we'll cover tomorrow (Wed) is on the exam, and nothing from our lab sessions. Additionally, simplified versions of HW problems are fair game. And I do mean simplified - there won't be any complicated integrals to work out. Mainly, you will have to set up the problems and demonstrate to me that you know what you're doing more than actually doing all the calculations in detail. For example, setting up the integral to find the field of a line charge, but not having to perform the integral.

I will have a set of 8-10 problems, all of essentially equal difficulty, and each of you will have to demonstrate knowledge of two of them for me. If you get really stuck at any point, I'll help you along in the problem (though at the cost of a few points).

I'm fairly certain most (all?) of you have not had an oral exam before, but it will be relatively painless, and most of you will do very well. If you understand the material so far and the homework solutions, you'll be fine. Don't get lost in mathematical detail when studying, focus on what is going on in the problems and how to set them up.

Friday's exam

You're ready. Get some sleep.

If you don't believe me, and want to cram anyway, I'd spend some time on Ch. 7, sections 2&3 in Griffiths, and then probably review the sections on Maxwell's equations (sans vector potential).

You will be rewarded if you can quickly recognize what to do with Maxwell's equations when (for instance) given an E field. You will also be rewarded if you have subjugated div, grad, and curl in spherical coordinates (formulas given).

Finally, you will be rewarded with bonus points if you remember what I said about tensors on Wednesday. Specifically, conductivity tensors.

PS - If you are unsure what a question means, or how to go about it tomorrow, don't hesitate to ask. More than likely, I will be willing to clarify the problem a bit or give you a hint to get you started. Also, show and turn in all your work, even if you think it illegible or unimportant. Partial credit is key.

Exam on Friday

A few stray hints for the exam on Friday.

• It is only an hour exam, so there will be four problems. You solve any two of them. Heavy partial credit is possible.
• There will be a formula sheet with all the basics. You are additionally allowed to bring in one sheet of standard 8.5x11 inch paper with whatever you like on it.
• Your formula sheet will contain fundamental constants and integrals you will need.
• Understand the derivation of the (approximate) dipole potential ...
• Reading through my old PH106 homework solutions might be helpful, just for some examples of worked problems. HW 1-4 are relevant, mostly.
• If need be, the exam will be scaled ... so relax :-)

I'll be around Bevill most of the day tomorrow if you want to drop by the office with questions. If you're busy in classes tomorrow, I'll try to respond to email questions rapidly.

Partial HW3 solutions

Here you go. I haven't typed up number 7 yet, and number 8 is incomplete. The rest are there, probably in more detail than you would like ...

If you didn't get every part of every problem, don't panic. They were very hard problems, and for the most part chosen to illustrate a certain point. If you mostly understand how these problems work out, but didn't quite get every last detail, I'll be happy with that (and partial credit will be generous).

For example, some of the problems (e.g., 5, 6, 8) have a relatively straightforward part followed by a much harder part. If you got the first part reasonably well, you will be fine on the exam, and I'd say you know what you are doing. The harder parts were mainly there to see what you could do, and make you think about things a little more. Again, if you didn't quite get everything, but found yourself thinking carefully about what the problem means, then mission accomplished.

Exam-wise, you can expect stripped-down versions of the easier parts of these problems. I can't stress enough: if you feel like you know what you are doing on the HW problems, but don't quite get them all the way worked out, you have no reason to panic.

On the other hand, panic should set in, a little, if you are not doing the homework (or at least reading the solutions after the fact).