Lecture 30  iq26

1. Current loop in a motor and in a generator

o Loop-magnet equivalence

o B exerts a torque on a current loop – physics principle leads to a motor

o Rotating loop leads to emf – physics principle leads to a generator

2.Chapter 22: Part-II: Gauss law beyond the simple symmetric cases

o Gauss law where S can have an arbitrary shape

o Clicker 29-1: Flux through one surface of a cube

o Clicker 29-3: Surface charge at a cavity

o Clicker 29-4: Find E at P due to surface charges

3. E near any surface of a conductor

o Relationship between E near a surface and the surface charge density

o Surface charges on a capacitor

o Applications:

o Surface charges on 2 || capacitor plates,

o Two parallel conducting plates: one with +5Q and one with -3Q.

4. Ampere’s law beyond the simple symmetric cases. See HW and Extra problems in both unit 2 and unit3.

Announcement:

Learning module:

Feedback will be incorporated into the lecture.

The learning modules will count as part of the homework score: instead of homework accounting for 15%, we now have homework at 12% and leaning modules at 3%.

Feedback on homework: The feedback will be used as the basic content for discussion sessions. In order to encourage participation, we have made HW feedback part of the iq clicker credit:

o iq clicker now counts for 5%,

o while feedback counts for 2%.

The latter is an easy 2%, as all you need to do is tell us which problem you found most confusing on a particular assignment and why. The feedback will be due on the same evening the homework is due, but the due time will be 11:50 to give those last-minute types a chance to enter feedback after completing the homework.

Words from Josh: “Please note that I will be reading the feedback, so if you enter something like "no comment" or a random string of keystrokes, you will not receive credit. Please make a sincere effort to give quality feedback, as it will have a direct effect upon the quality of your instruction.”