Griffiths – Introduction to Electrodynamics problems

 

Here are my solutions to various problems in David J. Griffiths’s excellent textbook Introduction to Electrodynamics, Third Edition. Obviously I can’t offer any guarantee that all the solutions are actually correct, but I’ve given them my best shot.

After some consideration, I’ve decided to repost this index to the solutions. I understand that some folks may be concerned that I am providing ‘free’ answers to problems that some students have been assigned as homework, but there are several points that should be made:

  • First, solutions to the problems in Griffiths’s textbooks are already readily available on the internet, as a cursory search with Google will reveal, so I’m not giving away anything that isn’t easily obtained by other means. Many of these solutions are provided by professors for their own courses.
  • If a teacher is concerned about students copying answers from the internet, s/he should consider making up their own problems. I did this for the courses that I taught in my 25 years as a university lecturer. For a field as rich as physics, it shouldn’t be too difficult to come up with original problems.
  • If you’re a student seeking to copy solutions, you should realize that you won’t learn much unless you make a genuine effort to solve the problem on your own first. Remember that in most universities, the majority of the marks for a course are obtained from exams, and if you sit an exam without having worked out problems on your own beforehand, your chances of passing are pretty low. In my experience as a teacher myself, I found that most students realize this and do make a genuine effort to learn the material on their own.
  • Finally, judging by many comments I have received, my posts have provided many readers with different (and hopefully in many cases, clearer) explanations of sometimes difficult concepts, so their value goes beyond merely providing solutions to a few textbook problems. In most of my posts, I have tried to provide an explanation of the theory behind the problem in a way that makes sense to me, which usually involves filling in steps sometimes omitted in the textbooks.

These solutions are the only ones that I’ve worked out so far, so please don’t ask me to post “the rest of the chapters” as I haven’t worked on those yet. I will get to them eventually.

Chapter 1 – Vector analysis

1.61

Chapter 2 – Electrostatics

2.3, 2.4, 2.52.6, 2.7, 2.82.11, 2.12, 2.13, 2.14, 2.15, 2.16, 2.17, 2.182.202.21, 2.22, 2.23, 2.242.25, 2.262.27, 2.282.302.312.32, 2.332.35, 2.362.37, 2.382.39, 2.402.41, 2.42, 2.43, 2.442.462.472.482.492.50

Chapter 3 – Special Techniques

3.13.63.7, 3.10, 3.113.12, 3.133.143.153.17, 3.18(a)3.18(b), 3.193.213.223.233.243.253.263.27, 3.28, 3.29, 3.333.343.353.363.373.383.393.403.413.423.43, 3.443.45, 3.46, 3.47, 3.48a

Chapter 4 – Electric Fields in Matter

4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 4.10, 4.11, 4.12, 4.13, 4.14, 4.15, 4.164.18, 4.19, 4.20, 4.21, 4.22, 4.23, 4.24, 4.25, 4.264.27, 4.28, 4.29, 4.30, 4.31, 4.32, 4.33, 4.34, 4.35, 4.36, 4.374.38, 4.394.40

Chapter 5 – Magnetostatics

5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 5.10, 5.11, 5.12, 5.13, 5.14, 5.15, 5.165.17, 5.18, 5.19, 5.205.21, 5.22, 5.23, 5.24, 5.25, 5.26, 5.27, 5.28, 5.29, 5.30, 5.315.32, 5.33, 5.34, 5.35, 5.36, 5.375.38, 5.39, 5.40, 5.41, 5.425.43, 5.44, 5.45, 5.46, 5.47, 5.48, 5.49, 5.50a5.51, 5.52, 5.53, 5.54, 5.555.56, 5.57, 5.58, 5.595.60, 5.61

Chapter 6 – Magnetic Fields in Matter

6.1, 6.2, 6.36.4, 6.5, 6.7, 6.8, 6.9, 6.10, 6.11, 6.12, 6.13, 6.15, 6.16, 6.17, 6.18, 6.19, 6.216.22, 6.236.246.25, 6.26, 6.276.28

Chapter 7 – Electrodynamics

7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.87.9, 7.10, 7.11, 7.12, 7.13, 7.14, 7.15, 7.16, 7.17, 7.18, 7.19, 7.20, 7.21, 7.22, 7.23, 7.24, 7.25, 7.26, 7.27, 7.28, 7.29, 7.30, 7.31, 7.32, 7.33, 7.34, 7.357.36, 7.377.38, 7.39, 7.40, 7.41, 7.437.44, 7.45, 7.46, 7.47, 7.48, 7.49, 7.50, 7.51, 7.52, 7.53, 7.54, 7.557.56, 7.57, 7.58, 7.59, 7.60

Chapter 8 – Conservation Laws

8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 8.10, 8.11, 8.12, 8.138.14

Chapter 9 – Electromagnetic Waves

9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 9.10, 9.11, 9.12, 9.139.14, 9.15, 9.16, 9.17, 9.18a, 9.18b-c, 9.19a-b, 9.19c, 9.20, 9.21, 9.22, 9.23a, 9.23b, 9.24, 9.25, 9.26, 9.27, 9.28, 9.29, 9.30, 9.31, 9.32, 9.339.34, 9.35, 9.36, 9.37, 9.38

Chapter 10 – Potentials and Fields

10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 10.10, 10.11, 10.12, 10.13, 10.14, 10.15, 10.16, 10.17, 10.18, 10.19, 10.20, 10.21, 10.22, 10.23, 10.24, 10.25, 10.26

Chapter 11 – Radiation

11.1, 11.2, 11.3, 11.4, 11.5, 11.6, 11.7, 11.8, 11.9, 11.10, 11.11, 11.12, 11.13, 11.14, 11.15, 11.16, 11.17,  11.18,  11.19, 11.2011.21, 11.22, 11.23, 11.24, 11.25, 11.2611.27, 11.28, 11.29, 11.30a, 11.30b, 11.31

Chapter 12 – Electrodynamics and Relativity

12.1, 12.2, 12.3, 12.4, 12.5, 12.6, 12.7, 12.8, 12.9, 12.10, 12.11, 12.12, 12.13, 12.14, 12.15, 12.16, 12.17, 12.18, 12.19, 12.20, 12.21, 12.22, 12.23, 12.24, 12.25, 12.26, 12.27, 12.28, 12.29, 12.30, 12.31, 12.32, 12.33, 12.34, 12.35, 12.36, 12.37, 12.38, 12.39, 12.40, 12.4112.42, 12.43, 12.44, 12.45, 12.46, 12.47, 12.48, 12.49, 12.50, 12.51, 12.52, 12.53, 12.54, 12.55, 12.5612.57, 12.58, 12.59, 12.60, 12.61

53 thoughts on “Griffiths – Introduction to Electrodynamics problems

  1. Abhilash Sharma

    its nice..
    one thing, soln of prob. 2.9 and 2.10 are not given though they r easy , but (b) part of 2.9 is very conceptual so upload that also…

    Reply
  2. Anonymous

    Has anyone worked through the many parts of problem 2.54? I would really appreciate if someone could help out with them, in particular part g.

    These solutions have been incredibly helpful otherwise. Thanks!

    Reply
      1. Anonymous

        Ahhh, my mistake. I was looking at the wrong edition. It turns out 2.54 in the 4th ed. is just about the same as 2.49 in the 3rd. Thanks for pointing out the mix-up!

        Reply
  3. Anonymous

    Thanks for maintaining this site! Much better than a solutions manual because you actually explain why you do what you do–so it’s possible to follow along and actually learn from the problems. I used your solutions for Griffiths’ Quantum Mechanics too!

    Reply
  4. Christian

    Hi, do you have the solution to the 8.9 Problem from the 4th Edition. I have my solution but I need to compare with someone.

    Reply
  5. David Dorenfeld

    Very helpful. Especially like the cross-referencing to other posts and the review of the theory before getting into the problem solution. Excellent.

    Reply
  6. karulg

    I usually use the official solution manuel, but for some of the problems i needed (more) explnations to really understand them. Thanks a lot.

    Reply
  7. darmudasir

    imagine a uniform magnetic field , pointing in z direction and filling all the space .A positive charge isat rest ,.Now if magnetic field is turned off ,in what direction does the charge move .plz explain

    Reply

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