Electricity, Magnetism, and Thermodynamics

Oberlin College Physics 111

Syllabus for Spring 2010

Teacher (lectures): Dan Styer, Wright 215, 775-8183, Dan.Styer@oberlin.edu
home telephone 281-1348 (2:30 pm to 9:00 pm only).

Teacher (laboratories): John Scofield, Wright 210, 775-8333, John.Scofield@oberlin.edu.

Office hours for Mr. Styer: Tuesday, 9:00 am to 10:00 am; Tuesday, 2:30 pm to 3:30 pm; or by appointment.

Course web site: http://www.oberlin.edu/physics/dstyer/P111. I will post handouts, problem assignments, and model solutions here.

Topics:

Discussion sections: Optional discussion sections meet on Thursdays and Mondays at 2:30 pm and Tuesdays at 11:00 am in Wright Laboratory 209.

Readings: Our textbook is D. Halliday, R. Resnick, and J. Walker, Fundamentals of Physics, 8th ed. (Wiley, New York, 2008). One great feature of this text is that, in addition to end-of-chapter questions and problems, it has "checkpoint" questions embedded in the reading. These are quick questions that make sure you're following the reading correctly. As you read the book you should perform these checkpoints as you come to them, and check your answers against the ones given in the back of the book.

Lectures: In this course I will need to represent many different types of entities on the chalkboard simultaneously. To help keep these different sorts of things straight, I will use various colors. (Some students have found it helpful to take notes with a variety of colored pens.) I will use

the color:    to represent:
white    physical objects
yellow    mathematical lines and surfaces
red    charge and current
blue    electric field
green    magnetic field

Minute papers: I will end every lecture a minute or two early so that you can write a brief (one- or two-sentence) reaction to the state of your knowledge concerning this course. Write this reaction, and your name and computer mail address, on a slip of paper and hand it in to me as you leave class. I will use these reactions to plan the next lecture and the future path of this course. Your most useful reaction would be a specific question: for example, "Does the electric field due to one charge change because of the presence of a second charge?" Other possible reactions would be indications of general interest ("I didn't follow the use of spherical symmetry with Gauss's Law.") or general questions ("Why should I care about this stuff, anyway?"). Please avoid questions of marginal relevance to this course ("How can I get that cute redhead in the second row to notice me?").

The ability to answer questions is an important skill. The ability to ask them is too. The problem assignments hone your answering skills, and the minute papers hone your asking skills.

Problem assignments: The problem assignments in this course are not a dry appendage designed to keep you indoors on sunny days. Instead, the problems are central to your learning in the course. Problem solving is a more active, and hence more effective, way to learn than reading text or listening to lecture. Problems will be posted on the course web site every Wednesday and are due at the beginning of class the following Wednesday unless there is an exam. My model solutions will be posted at the end of this class, so late assignments cannot usually be accepted. (I may make an exception in the case of a medical or family emergency, but in most cases it is to your advantage to move on to the next assignment rather than to let old work pile up.) In writing your solutions, do not just write down the final answer. Show your reasoning and your intermediate steps. Describe (in words) the thought that went into your work as well as describing (in equations) the mathematical manipulations involved.

For most problems assigned I will also list one or two "warm-up problems". If you find the assigned problem too complex or too abstract, then try the warm-up problem as an easier or more concrete exercise involving the same concept or skill that the main problem addresses. Working the warm-up should help you with the assigned problem. These warm-ups are not required and should not be turned in.

I encourage you to collaborate or to seek printed help in working the problems, but the final write-up must be entirely your own: you may not copy word for word or equation for equation. When you do obtain outside help you must acknowledge it. (E.g. "By integrating HRW equation (29-41) I find that. . ." or "Employing the substitution u = sin(x) (suggested by Carol Hall). . ." or even "In working these problems I benefited from discussions with Mike Fisher and John Silsbee.") Such an acknowledgement will never lower your grade; it is required as a simple matter of intellectual fairness. Each assignment will be graded by a student grader working under my close supervision.

Laboratories: Your laboratory work is an important part of this course, both for its own sake and for the light it sheds on the lecture material. The laboratory is also a good place to question, explore, and generally have fun. Laboratory sections meet for three hours once a week on either Tuesday, Wednesday, or Thursday afternoons starting promptly at 1:30 pm in Wright 214. You must receive a passing lab grade to pass this course. Additional information about laboratory will be distributed at your first lab meeting. There will be laboratory-related questions on the exams.

Exams: There will be three one-hour exams and one two-hour final exam. The three hour exams are scheduled for 9:00 a.m. (class time) on 10 March, 14 April, and 28 April. The final will be at 9:00 to 11:00 a.m. on Thursday, 20 May (the time set by the registrar). I will drop the lowest hour's worth of exam score in determining your grade (i.e. either the score of one hour exam or half the score of the final). No collaboration is permitted in working the exams. You may consult the text listed above and your own notes that fit on both sides of one 8 1/2 by 11 inch page of paper, but no other material. (In particular, your lab manual and lab notebook are not permitted.) Calculators are permitted. Before each exam I will distribute a sample exam consisting of exam questions that I have given in previous incarnations of this course.

At each exam you're allowed to bring your text and one sheet of paper with your own notes. (You may also, of course, make notes in the margins of your text.) What are the reasons for these rules?

Guest lectures: The Department of Physics and Astronomy periodically invites visiting scientists to lecture at Oberlin. I will announce these visits in class. If you attend the guest lecture and submit to me a one-paragraph description through this course's Blackboard site, you will be awarded 20 extra-credit problem-set points.

The purpose of the guest lectures is to broaden your horizons: to show you physics as it is done today and to present you with a viewpoint different from my own. You will not understand everything that the visiting speakers say . . . neither will I! One objective of the guest lectures is to show you how to get something out of a talk even when you don't understand everything in the talk.

Grading: Your final numerical grade will be compounded of 25% lab, 37.5% problem assignments, and 37.5% exams. On a 40-point scale, those with 40-36 points earn the grade "A", 35-30 points earn the grade "B", 29-20 points earn the grade "C", 19 or fewer points do not pass.

Reserve reading: The following books are on reserve in the Science Library. (They are located on shelves along the south wall, not far to your right when you enter, near some comfortable chairs to encourage browsing.) Our text is

These two texts treat the subject matter of this course from a more advanced and/or idiosyncratic point of view: While this one treats these matters from a more elementary and algorithmic point of view: Tensors, cross products, and completely antisymmetric rank-2 tensors: Two books particularly useful for thermodynamics are: You will undoubtedly notice that the problems and exams in this course, or any other physics course, exercise not only your knowledge of physics but also your skills in solving problems. You will find many hints for honing your problem-solving skills in the books And be sure to browse in

Tentative Laboratory, Exam, and Lecture Schedule

Electricity
Week 1     Lab: Organizational Meeting (brief)
8 February     Introduction
10 February     Electric Charge, Electric Force, and Electric Field
12 February     Visualizing Electric Field: Arrows, Field Lines, and Flux
Week 2     Lab: Electrostatics
15 February     Gauss's Law I
17 February     Gauss's Law II
19 February     Electric Potential
Week 3     Lab: Mapping Electric Potentials and Fields
22 February     Conductors in Electrostatic Equilibrium
24 February     Capacitors
26 February     Electric Potential Energy
Week 4     Lab: None
1 March     Current: Charge in Motion
3 March     Circuits I: Informal
5 March     Circuits II: Formal
Week 5     Lab: DC Circuits I
8 March     Electrical Safety, Shielding, Grounding
10 March     First Exam
12 March     Discharge of a Capacitor: Physics by Common Sense
Magnetism
Week 6     Lab: DC Circuits II
15 March     Magnetic Forces on Moving Charges
17 March     Magnetic Forces on Currents and
    Magnetic Field Made by a Single Moving Point Charge
19 March     Making Magnetic Field
Electromagnetism
Week 7     Lab: Using an Oscilloscope
22 March     Making the Equations Consistent
24 March     Making E by Changing B
26 March     Implications of Faraday's Law for Circuits
(Spring Break)
Week 8     Lab: Solar Cell
5 April     Uses of Inductors
7 April     Alternating Current Circuits I
9 April     Alternating Current Circuits II
Week 9     Lab: Measurement of Magnetic Field
12 April     Alternating Current Circuits III: LCR circuit
14 April     Second Exam
16 April     Something is Missing
Week 10     Lab: AC Circuits I
19 April     Maxwell's Equations and Light
21 April     Electromagnetic Energy and Momentum
23 April     Polarized Light
Thermodynamics
Week 11     Lab: AC Circuits II
26 April     Fluids and Pressure
28 April     Third Exam
30 April     Temperature
Week 12     Lab: Polarization of Light
3 May     Heat and Work
5 May     Heat Capacities; Adiabatic Changes; the Carnot Cycle
7 May     Efficiency of Carnot Engines
Week 13     Lab: Calorimetry
10 May     The Second Law
12 May     Definition of Entropy
14 May     What is Entropy?
Final exam: 9:00 -- 11:00 am, Thursday, 20 May.