# Physics 1b Practical -- WINTER 2008

## Course Description

9 units (4-0-5)

An introduction to electricity and magnetism with an emphasis on learning from practical examples and applications. The assignments include activities using a take-home lab kit.

Winter 2008
Lecturer: David Politzer
e-mail: politzer at theory.caltech

The first electric motor that produced serious torque was designed and built by Peter Barlow in 1822, Here are two pictures of his handiwork: 1 and 2. Faraday's earlier effort was kind of wimpy -- but ground-breaking, nevertheless. Here is a picture of an apparatus of his design, saved from his laboratory about a decade later.

### Capacitors Do Calculus!

An RC circuit is the simplest example of an analog signal processing device. Depending on the chosen values of R and C, the output voltage can be chosen to be the time derivative or the integral of the input voltage. Here are the formulas and a simple five-line Math 1 derivation: as postscript or as pdf.

In previous years, students requested that the class average quiz scores be posted. So, here they are: Quiz 1 average = 8.2 +/- 1.0; Quiz 2 average = 7.2 +/- 1.6; Quiz 3 average = 8.6 +/- 1.5; Quiz 4 average =7.6 +/- 1.4; Quiz 5 average = 6.1 +/- 1.4; Quiz 6 average =7.8 +/- 1.7; Quiz 7 average =6.9 +/- 1.4

Here is a portrait of old Ben Franklin, in which he had the artist include a depiction of his electrical storm alarm. (It's the gizmo hanging to the left of his head.)

## Help Lab moves to Sundays

### Help Lab will be staffed Sunday evenings, 8 to 11pm, replacing Mondays, which are now cancelled. Tuesdays remain as before.

The Help Lab is located in the Student Workshop, room 74, in SAC, under/between Dabney and Blacker (two doors to the left of the laundry room, right by the door that opens out to California Blvd. It will generally be staffed two evenings each week. Access for replacement parts at other times is by South Campus Master.

Help Lab times:

Staffed Help Labs are Sundays 8-11pm and Tuesdays 8-11pm.

Lab books for Ph 171 students (only) are due Thursdays by 3:00pm and will reappear Friday by 2:00pm.

Paper copies of all handouts, e.g., course calendar, quizzes, homework solutions, etc., are available in Bridge, 1st floor hall between East and West, shortly after they've been distributed in recitation sections. All are also posted here, on-line, where there may also be occasionally posted links to yet more information of potential interest.

Some students inquired whether they could use a previous edition of our textbook instead of the 7th (and thereby save some cash). I certainly think so. However, you will be responsible for the homework problems as assigned from the new edition. Typically, they have different numbers in previous editions, but they are all there in the 6th edition and virtually all in previous ones. Just look.

As per request of ASCIT and the BOC a few of years ago, here is a copy of their policies form, filled out for Ph 1 Prac at that time. The same comments apply to this current term. (You'll want page 2, too.) REMEMBER THAT ANY INDIVIDUAL QUIZ OR EXAM MAY HAVE INSTRUCTIONS WHICH OVERRIDE THESE.

Physics or logistical questions may be directed to the lecturer via e-mail if you can't do it in person, e.g., before or after lecture, Tuesday help lab, his office, etc. Questions and answers that might be of interest to other students will be posted here: Q&A (without identifying the questioner by name). (There's one there right now.)

Interested in doing the Prac Labs (only) for credit, e.g., enrolled in Ph 1 Analytic? Register for Ph 171 and click on one of the following versions of the relevant note: .ps, .pdf, or .html.

ZAP! is NOT your traditional, "cookbook-style" lab manual. The observations recorded here (that's .ps) may help you avoid considerable frustration during the next two terms. You'll also have a way to help next year's students. (.pdf version here and .html here.)

A former Ph 1 Prac TA, now out in the "real world," moved some of the advice he wrote for students to his personal Web page. His advice on writing up lab reports is clear, concise, and might prove helpful. If you back up and go to its parent directory, you might find other things of interest.