Welcome to the homework assignment page for Classical Electrosynamics (I) course (PHY 316) taught by Professor Vadim Kaplunovsky in Spring 2016 (unique #55930).
Most homework problems are taken from the Griffith's textbook Introduction to Electrodynamics; such problems are listed by their numbers in the textbook (page number in parentheses) according to the 4th edition. Note: if you have an older edition of the textbook, the problem numbers would be different!
If a homework set has any non-textbook problems, I shall either type it full at the appropriate place on this page, or else give a link to a separate TeX–generated PDF file.
By default, each problem is worth 10 points. But some problems may be woth more or fewer points; in that case I shall write down the pointage in brackets right after the problem number.
Once a homework is collected, I post the solutions in TeX–generated PDF format. The solutions will be linked to this page at the appropriate place.
Note: if for any reason you cannot come to the class on the day a homework is due, then scan your homework (or take a clear picture with a digital camera or cellphone) and email it to me and to the TA. Please don't waste time asking for my permission, just scan your work and email it, and make sure to do it before the end of the class on which the homework is due.
Reading assignments: textbook sections §1.1 and §1.4.
Textbook problems from chapter 2: 2.2 (page 62), 2.3 (page 65), 2.5 (page 65), 2.6 (page 65), 2.15 (page 76), 2.16 (page 76), 2.18 (page 76).
Textbook problems from chapter 1:
1.6 (page 8), 1.11 (page 15), 1.13 (page 15),
1.15 (page 18), 1.16 (page 18), 1.18 (page 20), 1.20 (page 20).
No non-textbook problems in this set.
Update 1/21: The last four problems from chapter 1 (1.15, 1.16, 1.18, and 1.20) are postponed to the next homework set.
Due January 26 (Tuesday); solutions.
Textbook problems from chapter 1:
1.15 (page 18), 1.18 (page 20), 1.20 (page 20), 1.26 (page 24),
1.46 (page 49–50), 1.48 (page 52), 1.49 (page 52),
1.61 (page 56) [15 points], 1.62 (page 57) [15 points].
Textbook problems from chapter 2: 2.20 (page 80), 2.21 (page 83), 2.22 (page 83).
No non-textbook problems in this set.
Update 1/27: Problems 1.46, 1.48, and 1.49 about the δ–functions are postponed to the next homework set.
Due February 2 (Tuesday); solutions.
Textbook problems from chapter 1: 1.46 (page 49–50), 1.48 (page 52), 1.49 (page 52), 1.64 (page 58–59).
Textbook problems from chapter 2:
2.48 (page 108), 2.53 (page 109) [15 points],
2.39 (page 102–103), 2.42 (page 104), 2.43 (page 107),
2.34 (page 95), 2.35 (page 96), 2.40 (page 103), 2.60 (page 112)
.
No non-textbook problems in this set.
Update 2/3 (3AM): Problems 2.34, 2.35, and 2.60 are postponed to the next homework. Problem 2.40 is canceled.
Due February 9 (Tuesday); solutions.
Textbook problems from chapter 2:
2.34 (page 95), 2.35 (page 96), 2.60 (page 112).
Note: for problem 2.60, the textbook answer is wrong,
it's a typo!
Textbook problems from chapter 3:
3.1 (page 118), 3.3 (page 119), 3.4 (page 119), 3.37 (page 160).
Notes: for problem 3.1, first read textbook §3.1.4 carefully;
for problem 3.4, average the electric field as a vector.
No non-textbook problems in this set.
Update 2/11: No problems are postponed this time, please do all 7 problems.
Due February 16 (Tuesday);solutions.
Six textbook problems from chapter 3: 3.5 (page 124), 3.7 (page 129), 3.10 (page 130), 3.11 (page 130) [15 points], 3.41 (page 161) [15 points], 3.58 (page 166).
Two non-textbook problems:
One more textbook problems from chapter 3: 3.40 (page 161).
Due February 23 (Tuesday);solutions.
First, read carefully §3.3 of the textbook, especially the examples which I did not discuss in class. Also, read my notes on the variable separation method.
Textbook problems from chapter 3: 3.13 (page 140), 3.14 (page 140), 3.16 (page 141) [15 points], 3.17 (page 149), 3.19 (page 149), 3.26 (page 150) [15 points], 3.43 (page 162) [15 points].
No non-textbook problems in this set.
Due March 1 (Tuesday);solutions.
Textbook problems from chapter 3: 3.35 (page 160), 3.27 (page 154), 3.44 (page 162).
Textbook problems from chapter 4:
4.4 (page 170), 4.6 (page 172), 4.30 (pages 205–206),
4.10 (page 176), 4.11 (page 176), 4.16 (page 184) [15 points].
No non-textbook problems in this set.
Update 3/8: problem 4.16 is postponed to the next homework set.
Due March 10 (Thursday); solutions.
Textbook problems from chapter 4: 4.16 (page 184), 4.36 (page 206–207), 4.37 (page 207), 4.22 (page 196), 4.25 (page 197), 4.19 (page 191), 4.26 (page 202), 4.28 (page 204).
No non-textbook problems in this set.
Due March 24 (Thursday after the spring break) ;solutions.
Updated 3/27: added 2 non-textbook problems and extended the due date to April 5.
First, two reading assignments:
Second, four textbook problems from chapter 5 about magnetic forces and electric currents:
5.3 (page 216), 5.4 (page 223),
5.10 (page 228) [15 points], 5.6 (page 223).
Note: in problem 5.10, use textbook eq. (5.39) for the magnetic field and mind its non-uniformity!
Third, two non-textbook problems:
Finally, four more textbook problems from chapter 5 about the Biot–Savart–Laplace Law:
5.9 (page 228) [12 points], 5.11 (page 229),
5.12 (page 229) [12 points], 5.50 (page 259)[12 points].
Due April 5 (Tuesday); solutions.
Textbook problems from chapter 5:
5.18 (page 240), 5.24 (page 248), 5.26 (page 248),
5.30 (page 249), 5.32 (page 251),
5.36 (page 255) [15 points], 5.58 (page 263).
Textbook problems from chapter 6:
6.1 (pages 270–271), 6.4 (page 271) [15points].
No non-textbook problems in this set.
Due April 12 (Tuesday); solutions.
First, an expanded textbook problem 6.6 (page 274) [15 points].
For each substance listed in the problem, google-up its structure: is it atomic, molecular, or ionic?
For atoms, look up their electron-shell structures;
for the ions, find the electron shell structure of the ion rather than the neutral atom;
for the molecules, find the type of each chemical bond and which electrons do they involve
(in terms of the shells thay are taken from).
Then see if all the electrons form spin-up/spin-down pairs, or if there are some un-paired electrons.
For the metallic solids, make sure to distinguish between the free (conducting) electrons and the remaining ion cores.
Given all these data, decide if the substance should be diamagnetic or paramagnetic, and explain your reasoning.
And now, six more textbook problems from chapter 6:
6.3(b) (page 270),
6.7 (page 276), 6.8 (page 276), 6.10 (page 277),
6.13 (page 282), 6.15 (page 284), 6.17 (page 287).
Due April 19 (Tuesday); solutions.
Textbook problems from chapter 7:
7.1 (page 301), 7.3 (page 302) [15 points], 7.5 (page 305),
7.7 (page 311), 7.8 (page 311), 7.12 (page 316),
7.17 (page 320–321),
7.19 (page 321) [15 points]. 7.51 (page 348) [15 points].
Notes:
In problem 7.19, start by deriving a Biot–Savart–Laplace–like formula
for the induced electric field.
Then integrate over the toroid's length exactly as in textbook example~5.6.
(the magnetic field of a circular loop).
In problem 7.51, first argue that B(x,y,z;t)=B(x-vt,y).
Then write down the vector potential A(x-vt,y), and use it to find the induced electric field.
Due April 28 (Thursday!); solutions.
Textbook problems from chapter 7:
7.22 (page 327), 7.25 (page 327), 7.30 (page 331),
7.29 (page 331), 7.31 (page 321–332), 7.33 (page 332),
7.34 (page 336), 7.40 (page 342), 7.60 (page 351) [15 points].
Notes:
In problem 7.30, think of a coaxial cable with a thick inner wire (wth uniformly distibuted current)
but very thin insulation and very thin outer wire.
In problem 7.60, first read
my notes on the divergence and curl of the B field,
look carefully at eqs. (9–23), and find an extra term in ∇×B
when ∇·J≠0.
Then relate that extra term to the displacement current.
Due May 5 (Thursday); solutions.