Office Hours and Midterms

Folks,

I'll be in 334AP from ~1pm tomorrow until ~3pm tomorrow. Drop by to chat about the final, or to pick up your midterm. See you then/there!

Review Questions

Why wait? If you're anxious to get started solving questions that will likely appear in a similar form on the exam, take a look at what I just posted.

Mark will discuss some of these tomorrow.

Don't worry about the ones I crossed out.

PA Session on Monday

One student asked about a PA session on Monday. Just to confirm, there will be no PA session on Monday. However, I will have extended hours early next week. I will post the hours on Sunday, once my schedule for next week stabilizes a bit more.

Last Lecture

Due to a family issue, I have asked Mark to give the last lecture (linear motors) and also to give you a summary of the likely questions to appear on the exam. I will also post sample questions here over the weekend if you check back.

Office Hours Location for Tonight

Tonight during office hours you can find me in 334AP, instead of in my office. I'll be there from 6pm until 7pm.

Missed Transformers Lab

Chris Raum tells me that the following students did not do the transformers lab. Are any of you planning on doing the lab? If so, you are running out of time to let me know.

Haidar Al-Aubiydy
Awais Cheema
Mohy-El-Din Hamdy
Matthew Holmes
Lohit Jalemu
Balenthiran Jeyabalasingam
Mohammed Miah
Thai Thanh Nguyen
Lawrence Wolfgram
Zain Zia

Missed Magnetostatics Labs

Lado wrote me this email:

Professor,
Other students that have missed the magnetostatics lab due to Thanksgiving and have not made it up yet are:
Razak Abdul
Haidar Al-Aubiydy
Mohy-El-Din Hamdy
Matthey Holmes
Lohit Jalemu
Christopher Mah
Zhe Ouyang

-Lado

If your name is on the list, you should contact Lado at lado_removethis_@rogers.com and arrange your make up lab time ASAP.

Make-up Labs

Some people missed certain labs through no fault of their own, so I'd like to give those people an opportunity to perform the labs. We will do so next week during the "PA sessions". Please send me an email if you need to do a lab, so I can straighten out which TAs are required. Let me know which day you normally attend labs, and which lab you need to perform.

Midterm Solutions

I posted the solutions to the midterm questions. Please review your marks, and if there is any problem see me tonight between 6pm and 7pm in 7044MC, or before or after class, or send me an email describing the problem.

The Last Lab

Your last lab is another computer-based experiment. This time it's all about magnetostatics (compared to the first lab which was about electrostatics). In this lab, you'll be looking at magnetic fields due to a ring of current, and due to a solenoid. Enjoy!

PA Sessions for the Week of November 12th, 2007

This week's PA sessions will be based on the PDF document containing the problems that Mark sent me recently. He'll be your TA for this coming week.

Office Hours

Folks,

I need to cancel my office hours tonight due to a family health issue. If you need to meet, just send me an email and we can arrange a time.

Blogger Test

Hi All,

Just testing this new Greasemonkey LaTeX extension for Blogger. It enables me to write an equation in LaTeX, for example, "\vec{E}=k\frac{q}{r^2}\hat{r}" and get the output formatted like so:

.

Not too shabby!

Motors Lab

The lab for this week is all about stepper motors. You can find the lab documents HERE and HERE.

Midterm Results

Hi All,

Just a note to let you know that this week we will be correcting your midterms. Maybe I can get them back to you on Friday, but more likely next week.

Vector Calculus Reference

I found an interesting website with interactive demonstrations of numerous vector calculus concepts HERE. It's well worth your time to review the material on this website, especially the upcoming material on Green's Theorem and Stokes' Theorem.

Friday's PA Session Versus the Midterm

Make sure you read my post about this issue.

Midterm Example Questions

Folks,

Here are some example questions, and here are some more. This is the formula sheet you will be given. Feel free to ask me more questions tomorrow. I'll be in my office tonight as usual as well.

Next PA Sessions

Folks, your next set of PA sessions will focus on the following:

Problems taken from:

Field and Wave Electromagnetics, Second Edition, by David K. Cheng.

P.4-1, P.4-6, P.4-7, P.4-8, P.4-14, P.4-18

P.4-12, P.4-15, P.4-16, P.4-18, P.4-23, P.4-27

New Version of Xfmr Lab

My server is still dead. I'm working on moving everything over to a new machine.

Meanwhile, the TAs have given me an updated version of the Xfmr Lab. You can find your updated lab for this week HERE, and a supplement for the lab HERE.

Hints for the Transformer Lab

Thanks to Arvind for coming up with the following:

ELEC 3105

Basic EM and Power Engineering

Lab 5- The Transformer

(Please make sure you have the latest lab theory + instruction booklet)

Description of Experiments and Hints

Experiment (a)

This is a simple experiment, where we measure the coil resistances R1 and R2 of the transformer, as shown in Fig. 3 using a multimeter. Please remove all connections on the Transformer before you make the measurements.

Experiment (b)

In this experiment, we measure the turns ratio of the given transformer, assuming its ideal. Connect the Wavetech source to the primary and the measure the output voltage amplitude at the secondary and evaluate the v1/v2 ratio.

Experiment (c)

In this experiment, we compute the input impedance and its components (resistance and reactance) with the secondary short circuited. Hence, the simplified equivalent circuit Fig. 5 comes into the picture. Using the set up in Fig. 7, you will measure the current and voltage in the primary. Hence the ration v1/i1 must give the input impedance. Note that this will be complex as we have the effect of a resistance and an inductance connected in series for this set up as shown in Fig. 5. The resitance being R1+ a² R2 and inductance being 2(1-k)L1.

But first, you must figure out how to calculate a resistance and an inductance part of a load when you know the voltage and the current through them. Once you derive the relationships as given in the booklet, proceed to measure the voltage and current amplitudes and relative phase.

Experiment (d)

The purpose of this experiment is to measure the eddy current losses (Rc) and kL1. For this we open circuit the secondary and hence, Fig. 6 comes into effect. As in the previous experiment, you shall measure v1 and i1. From that you can estimate the effective series resistance and the inductance of the circuit in Fig. 6 Rs and Ls as before.

From Fig. 6 you will see that these values depend upon R1, (1-k)L1, Rc and kL1. But we already know the values of R1 (Expt (a)) and (1-k)L1 (half the value of the inductance found in Expt (c)), so to find the remaining unknowns, (Rc and kL1), you must derive the relationship (10) and then use the values of Rs, Ls, R1 and (1-k)L1 to compute Rc and kL1.

Experiment (e) & (f)

You will repeat the above experiment for increasing frequencies and plot the behavior of Rc and kL1 against frequency. Beyond a certain point, you will see a drastic change in the Reactance of the equivalent circuit. Give an explanation for this behavior.

Hint: May be some assumptions made to construct Fig.6 that you so dearly followed for all your calculations isn’t that good after all!

Experiment (g) & (h)

This is again a repetition of the previous experments but with 2 small changes:

1. you will connect a 10 ohm load to the secondary
2. you will model the resulting equivalent circuit looking “into” the source v1 as a resistance and an inductance in PARALLEL as against serial, as you have been doing till now.

Now with v1 and i1, you figure out how to measure the resistance and inductance connected in parallel. Use these relationships (13) to measure the values of Rp and Lp. Compare it with the ideal model described in (5) and speculate why your results don’t satisfy that simple explanation, especially at low frequencies. Also the currents and the voltages distort at some value of v1 as you increase it. Note that point and explain why.

Hint: What do you remember of inductors, when it comes to DC currents and very high frequency AC currents?

Server Issue?

Hmmm.....my server seems to be dead, or at least the connection to it is dead. I'll fix it first thing tomorrow (fingers crossed). Meanwhile, you can find your lab for this week HERE, and a supplement for the lab HERE.

So what's this one about, you might ask....well, this week you'll look at transformers. I think it's safe to say that you've all dealt with transformers in some form in other courses, but in this course we will examine them using fundamental EM theory. We'll actually have to cover quite a bit of material before we're ready to give transformers the full EM treatment, but everyone can handle the lab this week because it is a measurements-type lab that you can later refer back to when we cover the theory. Hopefully the theory we develop will match the measurements.

Speaking about measurements and the value of measurement-based labs, consider this quote that I read recently on-line:

"One accurate measurement is worth a thousand expert opinions."
Author: Admiral Grace Hopper

(It's well worth your time to read about her.)

Labs this Week

Folks,

This week is a lab week, as originally planned. I'll post the lab later on this evening (as soon as I get my lap top up and running!).

Midterm Date

Folks,

In case you didn't come to class the few times we discussed this, the midterm has been scheduled for November 2nd (during class time). We'll discuss the contents of the midterm in class next week, likely on Wednesday.

First Injuries

You may have noticed that I wasn't lecturing today. I have a pulled periformus muscle, a pulled gluteus medius, and likely a pulled gluteus maximus. Talk about painful! Anyway, I had my first chiropractor session today, and already it feels "different" (not better yet, but at least a change). Hopefully I'll be back in the gym soon! ...oh yeah, and back to lecturing too :) .

Office Hours

Folks,

Some of you have been coming to my office during office hours, which is great! Just for the record, here are the office hours for myself and the TAs:

• Dr. MacEachern: Tuesdays, from 6pm-7pm. You can also try earlier (e.g 5:30pm) but no promises!
• Khaled: Khaled says just email him for an meeting, anytime! What an offer! His email address is: kmnay@doe.carlton.ca (spell Carleton correctly -- just trying to confuse the SPAMbots).
  
• Mark: 2pm-4pm Wednesdays in 5149ME
• Lado: 12pm-2pm Thursdays in 338AP
• Lidija: waiting for confirmation
• Barbora: 2pm to 3pm Wednesdays in 5169ME
• Arvind: 12pm-2pm Tuesdays in 6075MC
• Christopher: 10am-12pm Tuesdays in 7047MC

PA Sessions for the week of Oct. 15th

Folks,

Khaled is proposing the following questions from Cheng:

P.3-24, P.3-25, P.3-26, P.3-27, P.3-37, P.3-47, P.3-38, P.4-1, P.4-6, P.4-7, P.4-8, P.4-14, P.4-18

Plus, I've requested problems related to forces on conductors and also on image theory.

Lab #3 Download

You can find a PDF for Lab #3 HERE.

Note that it says "Lab #2", but don't fret, it's really Lab #3 for this year.

Give it a read, and have some fun with it tomorrow. It works rather well, and we'll be covering the material in class soon, so this gives you a good preview of what's to come in the course.

Lab #3

Hi Class,

I'll post up the materials for Lab #3 as soon as I get the "all clear" from your friendly neighbourhood TAs about the contents and functionality. It should be fine -- no changes from last year in any case.

Since today is a holiday, Section A1O is missing their lab for this week. No problem. You can do either of the following:

• Show up during any of the other sections this week, if you can fit the period into your schedule;
• Show up at the end of the term for a "make-up" lab period.

Enjoy the rest of the holiday!

PA Sessions for the Week of October 1, 2007

Don't forget: Everyone has PA sessions this week, and you should go to 4275ME for your session.

The PA problems are taken from:

Field and Wave Electromagnetics, Second Edition, by David K. Cheng.

P.3-11, P.3-13, P.3-15, P.3-18, P.3-20

It would be worth your time to take a quick look before you go to the session. Maybe you can stump Khaled!

Lab #2

Hi All,

Lab #2 can be found HERE.

Note that a few things in the Lab need to be edited (I will get an updated version from the TAs and replace the one I posted). Here's a summary of the changes:

1. The lab is being held in 4275ME (not 6030MC as stated in the lab).
2. You need an account on Nagui's lab network. He will make the accounts when you show up for the lab.
3. Step 4 on Page 3 of the lab handout states "Extract to W:/Maxwell". This location may change depending on Nagui's network configuration. The TAs (or Nagui) will tell you where you can save your files.

Otherwise I think the lab is straightforward. It's written as a "do this, find that" type of lab.

For your lab write-up, let's keep things simple. Just answer the questions that the lab poses in the order they are given. Keep your answers concise. You can capture screen shots of plots and include them in your report instead of redrawing plots from the screen. You can either write up your lab by hand, or you can type it up on the computers in the lab.

When the time is up, or you're done the lab, print out your lab write-up and give it to the TA before you leave. Make sure that the document is properly stapled together.

Course Notes Quick Fix

Well, I'm not happy. My webserver can be accessed from DOE or from off-campus, but as far as I can tell not from many (any?) locations on campus. That's why the links below are showing up as dead when you click on them.

For now, I've moved the course notes to a machine that CCS trusts. The links to the notes below should work. Let me know if there are any problems.

Anyone who was accessing the notes from home via Rogers Cable, Bell, etc., should have been able to download the notes without a problem. Let me know if that is not the case.

PA Session A3O

As mentioned below, the first PA session will be held today for section A3O. You can find an advance copy of the PA questions HERE.

Course Notes

Well, I was fighting with font embedding, but I think I've prevailed. You can find the course notes as follows:

1. Cover page and foreword (~40KB).
2. All slides, one per page as a PDF file (~30MB).
3. All slides, four per page as a PDF file (~15MB).

I would print these double sided, and then bind along the long edge. The cover page can go on the outer cover.

The IEEE will print 33 copies of the four-slides-per-page version, and 2 copies of the single-slide-per-page version (as requested in class; if you weren't in class, contact the IEEE to get your copy printed).

PA Sessions

Someone asked if the PA sessions will start this week.....that's a great idea! Actually, I had a meeting with the TAs on Friday, and we decided to start the PA sessions this week, and the labs will commence next week.

The Problem I Assigned

Hi All,

A few people didn't catch what I said about the "two media" and Coulomb's Law. So here it is again:

Suppose you have two different media, one with associated relative permittivity e1 (epsilon_1) and the other with e2. Recall in the Coulomb's Law equation that there is the relative permittivity embedded in the expression for k. Now, the question is this: suppose charge q1 is in media #1, and q2 is in media #2. Which permittivity do you use when finding the force acting on q1 due to q2 (and vice versa, which permittivity do you use for the force on q2 due to q1)?

Welcome 97.3105 Fall 2007

Well, we are off to the races with the start of the new term. I'd like to welcome you all to 97.3105. Hopefully you will find it to be an interesting and worthwhile course.

You can find this week's lectures HERE and HERE.

Lecture Notes for the Week of January 22nd, 2007

• Lecture notes for January 23rd are HERE.
• Lecture notes for January 25th are HERE.

Lecture Notes for the Week of January 15th, 2007

• Lecture notes for January 16th are HERE.
• Lecture notes for January 18th are HERE.

Why Study EM?

You might find this paper of interest.

Lecture Notes for the Week of January 8th, 2007

You can find this week's lecture notes HERE and HERE.

Frequently Asked Questions

How do you pronounce the last name MacEachern?

• MacEachern is a Scottish name. It is not as difficult to pronounce as it might appear. Spelled phonetically, I pronounce my last name as Mac Kakren.

How difficult is this course?

• The course is difficult unless you apply yourself and stay on top of the course material as it is presented in class. If you fall behind, make sure you catch up quickly. The material is cumulative in nature, and you cannot go long without running into problems if you are not up to date on the lecture material.

Can I register in the course as a special student?

• Generally the answer is yes, depending on your background education.

Letters, we get letters...

We get a lot of email. Don't be distressed if you don't get a reply right away, but if more than two days go by, then please follow up on the email.

When sending a course-related email, make sure that you include

"97.3105 W2007"

in the email subject line. This enables us to easily filter your email into an appropriate file folder. No, I'm not thinking about the trash :).

Registered Students

The students registered in the course at the time of this posting are as follows. If your name is not here, and you think it should be, then please let me know ASAP.

1. Ahmad, Talha
2. Al Azzouni, Haytham
3. Arksey, Christopher
4. Bansal, Anil
5. Bock, Katherine
6. Chidisiuc, Chiril
7. Haider, Rizwan
8. Hay, Michael
9. Lloyd, Emma
10. Mah, Christopher
11. Mantha, Divya
12. Miles, Alexander
13. Rajabalee, Nabiilah
14. Saini, Amaninder
15. Shen, Yizhe
16. Sooroojbally, Navishta
17. Stelescu, Octavian
18. Swan, Mark

First Post

Welcome to the 97.3105 blog. Eventually you will find links to course materials and information. I am just getting the site up now.