Physics 110B - Winter 2025
| Lectures: | TR
11:00-12:15 Psych 1902 |
| Discussions: | R
4:00-4:50 Phelps 1448 |
| R
5:00-5:50 Phelps 2514 |
http://hep.ucsb.edu/people/claudio/ph110b-w25
Announcements:
Course Description:
Electrodynamics, Maxwells equations, conservation laws, electromagnetic waves, potentials and fields for moving charges, radiation, special relativity.
Textbook:
Introduction to Electrodynamics, Griffiths, 5th edition. Same as 110A (amazon link).
The 4th edition is also fine.
I will be (mostly?) assigning homework problems from the book (5th edition).
I need to know if there are students with the 4th edition, so that I can pick problems that are in both the 4th and 5th edition.
Additional Material
Homework:
Homeworks should be turned in via Gradescope. Code: TBD
Note: the number of interesting/good E&M problems that one come up with is somewhat limited.
If you search hard enough on the web, you are likely to be able to find solutions to many of the assigned problems (or
to very similar problems). Apparently, the latest version of ChatGPT can actually solve hard, graduate level, E&M problems (!).
My recommendation is that you try hard to do the problems yourself, or with your study group.
If you do end up getting help from the internet or other sources, make sure you understand the solution, do not
just copy it down. Maybe just take a hint to get started and then finish things by yourself.
To be clear: I am not encouraging you to do this, but I recognize reality, and I also think that there is some learning value
in looking things up, but only after you have made a good effort. Careful: do not overdo it! Remember that in the end you
will need to solve exam problems all by yourself.
In any case: if you get help with your homework from any source (internet, friends, study group...), make a note of
it with your solution. You will not be penalized in any way, but honesty is always good.
Discussion Session Materials
Attendance to discussion session is not mandatory.
Exams and Grading:
There will be one midterm and one final.
The midterm will be on Tuesday, February 11 during normal class time.
The final will be Wedesday, March 19, 12-3 pm.
The final grade for this class will be calculated from a curve based on your scores on the Homework (15%), Midterm (35%), Final (50%).
For an example on how I previously arrived at the letter grades for a class, see this link.
If you miss the midterm for a good reason (eg: illness), your letter grade will be calculated based on the homework and final only.
If you miss the final you will be given an incomplete. You will take the Physics 110B final the next time that the class is being offered.
If, on the other hand, this is your last class that you need to graduate, we'll figure it out, somehow.
Midterm results
The midterm has been graded. You can pick up your graded blue book from Debbie Ceder, Broida 5014.
Here are the solutions (here is an addendum) Below is the score distribution.
Final Results
See this page.
Tentative Schedule (TBD):
Sections from Griffiths
- Jan 7: Physics Department Climate Document
- Jan 7: To insure that I do not miss your emails, use the string [110b] at beginning of the subject line.
- Feb 4: Information about the midterm
- The midterm is on Tuesday February 11.
- The midterm will cover the chapters in Griffiths covered up to and including those from the Week of February 3 (Tuesday's lecture only). (See Tentative Schedule at the bottom of the page)
- You can bring two sheets of notes to the exam. You can write on both sides.
- I will also distribute this formula cheat sheet with the problems.
- For practice: last quarter's midterm is here. And here are the solutions. NOTE: the midterm had four problems, but students had to solve only three of them.
- Here
is the distribution of scores for last quarter's
midterm.
- It is likely that the midterm will also include a few
quick multiple choice conceptual questions. TBD.
- There will be a review session on Sunday February 9, 12 noon, Broida 1640. I will not prepare anythinf special, I will just be there to answer questions. So: bring your questions
- Mar 15: Information about the final
- The final will cover all chapters in Griffiths listed in the Tentative Schedule below.
- Just as for the midterm
- You can bring two sheets of notes to the exam, you can write on both sides.
- Bring a blue book, and a pen or pencil.
- I will also provide various formulas....here they are.
- Practice finals are available in the Discussion Session Material for March 13 below.
- Mar 25: The final has been graded. Information here.
| Instructor: | Claudio Campagnari | |
|---|---|---|
| Email: | claudio@physics.ucsb.edu | |
| Office: | Broida 5125. Phone 805-893-8802. |
|
| Office hours: | Thursday 12:30-1:30, or by appointment, or whenever
you can find me. |
|
| Administrative Assistant: | Debbie Ceder | |
| Email: | dla@physics.ucsb.edu | |
| Office: | Broida 5014. Phone 805-893-2058. | |
| Teaching Assistant | Ziyue Wang | |
| Email: | zi-yue@ucsb.edu |
|
| Office hours: | Wednesday 3-5 pm |
|
| Learning Assistant |
Filippo Delzanno |
|
| Email: |
fdelzanno@umail.ucsb.edu |
|
| Office hours: |
Tuesday 3-4 pm Wednesday 1-2 pm |
|
| Learning Assistant |
Franklin Myhre |
|
| Email: |
fmyhre@ucsb.edu |
|
| Office hours: |
Tuesday 1-2 pm Thursday 1-2 pm |
|
| Graders |
Ivy Li and Zhengyu Wan |
|
| Email |
ili@ucsb.edu and zwan@ucsb.edu |
|
Course Description:
Electrodynamics, Maxwells equations, conservation laws, electromagnetic waves, potentials and fields for moving charges, radiation, special relativity.
Textbook:
Introduction to Electrodynamics, Griffiths, 5th edition. Same as 110A (amazon link).
The 4th edition is also fine.
I will be (mostly?) assigning homework problems from the book (5th edition).
I need to know if there are students with the 4th edition, so that I can pick problems that are in both the 4th and 5th edition.
Additional Material
- Wire size vs. current
- In the January 16 lecture we talked about the fact that magnetic forces do no work on charges, because the magnetic force q v x B is perpendicular to the velocity and therefore perpendicular to the displacement. There are some interesting examples in Griffiths Chapter 8.3. In the Fall version of the class I went through the first of these examples (Example 8.5 page 380 in the 5th edition and described at the bottom of page 373 in the 4th edition). As I said in class, I had trouble understanding the technique he used to solve the problem. This quarter I have decided to skip this subject to save some time for later. But it is interesting, here is a writeup from last quarter that explains Griffith's method (it also shows an alternative derivation).
- January 24: how to use Kirchoff's voltage law in a circuit.
- January 29: About polarization of reflected and transmitted waves: here.
- February 18: Alternative derivation
of the Lienard-Wiechert potential: here.
- February 23: Derivation of the fields from a charge moving at constant velocity ( Example 10.4 in Griffiths): here.
- March 4: A note on Natural Units: here.
Homework:
Homeworks should be turned in via Gradescope. Code: TBD
Note: the number of interesting/good E&M problems that one come up with is somewhat limited.
If you search hard enough on the web, you are likely to be able to find solutions to many of the assigned problems (or
to very similar problems). Apparently, the latest version of ChatGPT can actually solve hard, graduate level, E&M problems (!).
My recommendation is that you try hard to do the problems yourself, or with your study group.
If you do end up getting help from the internet or other sources, make sure you understand the solution, do not
just copy it down. Maybe just take a hint to get started and then finish things by yourself.
To be clear: I am not encouraging you to do this, but I recognize reality, and I also think that there is some learning value
in looking things up, but only after you have made a good effort. Careful: do not overdo it! Remember that in the end you
will need to solve exam problems all by yourself.
In any case: if you get help with your homework from any source (internet, friends, study group...), make a note of
it with your solution. You will not be penalized in any way, but honesty is always good.
| Homework Number | Due date | Problems | Solutions |
| 1 | Friday, January 17, 11:59
pm |
here |
here
|
| 2 | Friday, January 24, 11:59 pm | here |
here |
| 3 | Friday, January 31, 11:59 pm | here |
here
|
| 4 | Friday, February 7, 11:59
pm |
here |
here
|
| 5 | Note non-standard
due date Sunday, February 16, 11:59 pm |
here |
here |
| 6 | Friday, February 21, 11:59 pm | here |
here |
| 7 | Friday, February 28, 11:59 pm | here |
here |
| 8 | Friday March 7, 11:59 pm |
here |
here |
9 |
Not due for grading. But strongly recommend you look at this homework to help preparing for the final |
here |
here |
Discussion Session Materials
Attendance to discussion session is not mandatory.
| Date |
Questions |
Solutions |
|
| 1 |
January 9 |
here |
here |
| 2 |
January 16 |
here |
here |
| 3 |
January 23 |
here |
here |
| 4 |
January 30 |
here |
here |
| 5 |
February 6 |
here |
here |
6 |
February 13 |
Review midterm questions |
See below, in the Exams and Grading section, for solutions. |
| 7 |
February 20 |
here |
here |
| 8 |
February 27 |
here |
(Solutions are in the
book) |
| 9 |
March 6 |
here |
here |
| 10 |
March 13 |
Final
from Fall 2024 Practice Final from Fall 2024 |
Solutions
to F24 Final Solutions to F24 Practice Final Note: solutions for the F24 practice problem 2 are in cgs units |
Exams and Grading:
There will be one midterm and one final.
The midterm will be on Tuesday, February 11 during normal class time.
The final will be Wedesday, March 19, 12-3 pm.
The final grade for this class will be calculated from a curve based on your scores on the Homework (15%), Midterm (35%), Final (50%).
For an example on how I previously arrived at the letter grades for a class, see this link.
If you miss the midterm for a good reason (eg: illness), your letter grade will be calculated based on the homework and final only.
If you miss the final you will be given an incomplete. You will take the Physics 110B final the next time that the class is being offered.
If, on the other hand, this is your last class that you need to graduate, we'll figure it out, somehow.
Midterm results
The midterm has been graded. You can pick up your graded blue book from Debbie Ceder, Broida 5014.
Here are the solutions (here is an addendum) Below is the score distribution.
Final Results
See this page.
Tentative Schedule (TBD):
Sections from Griffiths
| Week of Jan 6 |
7.1 7.2.1 7.2.2 |
| Week of Jan 13 |
7.3.1 --> 7.3.5 8.1
8.3 (just the concept, see Additional
Material entry) |
| Week of Jan 20 |
8.2.2 (skipping the ugly vector algebra)
8.2.3 9.1.1 9.1.2 9.2.1 9.2.2 9.2.3 |
| Week of Jan 27 |
7.3.6 9.3 See also Additional Material entry dated
January 29. |
| Week of Feb 3 |
Tuesday's Lecture: 9.4.1 9.4.2 Thursday's lecture: 9.5.1 9.5.2 (not finished, to be continued) |
| Week of Feb 10 |
Midterm week Finished 9.5.2, 10.1.1 10.1.2 10.1.3 10.2.1 (Started) |
| Week of Feb 17 |
10.2.1 (finished) 10.3.1 (but see my
alternative derivation of the LW potential under Additional Material) 10.3.2 (skipped the algebra) Example 10.4 (see a complete derivation under Additional Material) |
| Week of Feb 24 |
11.1.1 11.1.2 11.1.3 (just the result)
11.1.4 11.2 |
| Week of March 3 |
Review of other courses: 12.1.3 12.1.4(i)
12.2.1 12.2.2 12.2.3 12.2.4 More review (possibly): 12.3.1 12.3.2 12.3.3 |
| Week of March 10 |
12.3.4 12.3.5 Problem 12.60 |