What is Electrodynamics: Definition and 416 Discussions

Electromagnetism is a branch of physics involving the study of the electromagnetic force, a type of physical interaction that occurs between electrically charged particles. The electromagnetic force is carried by electromagnetic fields composed of electric fields and magnetic fields, and it is responsible for electromagnetic radiation such as light. It is one of the four fundamental interactions (commonly called forces) in nature, together with the strong interaction, the weak interaction, and gravitation. At high energy, the weak force and electromagnetic force are unified as a single electroweak force.

Electromagnetic phenomena are defined in terms of the electromagnetic force, sometimes called the Lorentz force, which includes both electricity and magnetism as different manifestations of the same phenomenon. The electromagnetic force plays a major role in determining the internal properties of most objects encountered in daily life. The electromagnetic attraction between atomic nuclei and their orbital electrons holds atoms together. Electromagnetic forces are responsible for the chemical bonds between atoms which create molecules, and intermolecular forces. The electromagnetic force governs all chemical processes, which arise from interactions between the electrons of neighboring atoms. Electromagnetism is very widely used in modern technology, and electromagnetic theory is the basis of electric power engineering and electronics including digital technology.
There are numerous mathematical descriptions of the electromagnetic field. Most prominently, Maxwell's equations describe how electric and magnetic fields are generated and altered by each other and by charges and currents.
The theoretical implications of electromagnetism, particularly the establishment of the speed of light based on properties of the "medium" of propagation (permeability and permittivity), led to the development of special relativity by Albert Einstein in 1905.

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  1. M

    Flux Through A Sphere Surrounding A Parallelepiped

    Homework Statement The rectangular parallelepiped with sides ## a > b > c ## is filled with charge of constant density ## \rho ##. A sphere of radius ## 2a ## is constructed with its center at the origin. Find the flux through the surface of this sphere Homework Equations $$ \oint E \cdot...
  2. Moayd Shagaf

    Classical Griffiths Electrodynamics vs Pollack Electromagnetism.

    I try to learn electrodynamics as theoretical physicist, Now I study from Griffiths, I find it very good book and do the job! but the problem I need to learn electrodynamic to do future topics like Quantum Electrodynamics, and Pollack I find it good and modern, so my question is what is the best...
  3. T

    Classical Griffiths "Intro to Electrodynamics"

    Hi, I recently ordered the fourth edition of "Introduction to Electrodynamics" by Griffiths. However, I received the international version of the textbook. In my upcoming course, our homework will be made up of problems coming directly from the original version. So, are the problems in the...
  4. H

    Faraday's Law: Induced Voltage and Current in a Loop with Resistance R

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  5. spareine

    Sketch of the electric field of a laser beam

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  6. Jianphys17

    Electrodynamics: Comparing Purcell & Griffiths Textbooks

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  7. Vaibhav Sahu

    Propagation of EM Waves in metamaterials

    We have materials that have negative effective permittivity and permeability. In such materials, when the product of permittivity and permeability is negative, solving the wave equation yields a wave with a purely imaginary wave number. Does this mean complete attenuation of the wave ?
  8. Mind----Blown

    What does Griffith mean by this hint? [Electrodynamics]

    I was solving the problems given by Griffith in his book 'Introduction to Electrodynamics' and stumbled across this question. "Because sigma (conductivity of the medium) is a function of position, the equation 7.5 does not hold" --i get this point; current density isn't constant and so its...
  9. MathematicalPhysicist

    Thread about Jackson's Classical Electrodynamics 3rd edition

    In this thread I gather my questions concerning derivations in the textbook of equations and of solutions to the exercises. I hope every student and professional will benefit from this thread. I'll start in the next post.
  10. A

    Classical Companion book for Electrodynamics by Jackson

    I am studying electrodynamics, in a few more months I have the qualification exam. The guide text is classical electrodynamics, Jackson. I find that book is higher my current level. I have the math tools, but what book do you recommend to use before the Jackson.
  11. J

    Books on Covariant formulation of Electrodynamics

    Hello! I am an undergraduate currently enrolled in a course on theoretical physics. One big part of the course is on the classical field theory of electromagnetism(on its covariant formulation using Lagrangians mostly). So, I would like to ask which are some good books on the subject. Thanks in...
  12. qnach

    I Original references for Hertz's experiments

    There are many website about the apparatus of Hertz's experiments, i.e. http://www.sparkmuseum.com/BOOK_HERTZ.HTM http://earlyradiohistory.us/1901hz.htm http://people.seas.harvard.edu/~jones/cscie129/nu_lectures/lecture6/hertz/Hertz_exp.html There are many pictures showing the apparatus of...
  13. RGalbiati

    Classical Good exercises book for relativistic electrodynamics

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  14. P

    B Why Need Covarient Form of Electrodynamics?

    hello this is my first topic here and i hope good discussion or answer to my question As i understand the Maxwell equation keep its form in all frames so why i need to make a covarient formulation form of electrodynamics ? for example what the covarient form of continuity equation give me !
  15. 1

    Why can't I use this equation for the magnetic field?

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  16. A

    Classical Book to learn classical electrodynamics

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  17. Narayanan KR

    Can capacitors receive EM energy?

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  18. DavideGenoa

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  19. S

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  20. G

    Field-free formulation of ED: Conservation laws?

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  21. G

    Faraday cage in electrodynamics (with currents)

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  22. Y

    Electrodynamics problem - force equilibrium

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  23. Babbeus

    I Lorentz derivation of length contraction in electrodynamics

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  24. L

    Studying Resources for reviewing Electrodynamics

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  25. physicality

    I How to show that Electrodynamics is conformally invariant?

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  26. thefurlong

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  27. qnach

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  28. W

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  29. F

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  30. X

    Courses Is Jackson's Electrodynamics as hard as they say it is?

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  31. M

    Over what frequency range are Maxwell's equations valid?

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  32. L

    Other Research topics in Statistical Physics

    Currently I'm in the last year of the Physics course and I've been thinking about working in a project of undergraduate research, specifically in Statistical Physics. Two years ago I've already done a project like that in Fluid Mechanics combined with Gauge Theories and in that project I've...
  33. S

    Quantum Book on quantum electrodynamics

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  34. DuckAmuck

    Electric Charge Interacting with Magnetic Monopole

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  35. It's me

    How does ∇ × J = 0 relate to B = 0 in Maxwell's equations?

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  36. debajyoti datta

    A What is the divergence of 1/r^n for positive integer n in physics?

    I have read in Griffiths electrodynamics that divergence of 1/r^2 is delta function and I thought it was the only special case...I have understood the logic there... but a question came in mind...what would happen in general if the function is 1/r^n ...where n is positive integer>0...because the...
  37. F

    Calculate the charge of a density distributed along z axis?

    Homework Statement How do I find the total charge from a material with a charge density given by \rho =10^{-9} \text{cos}\left ( \frac{z}{z_0}\right ) C/m^3 that exist between \frac{-\pi}{3}z_0<z<\frac{\pi}{3}z_0. Homework Equations None I can think of. The Attempt at a Solution Attempt #1...
  38. adremja

    EM wave with circular polarization interferes with conductor

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  39. R

    Conceptually Relating 2nd Partials to Electrodynamics

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  40. PhiowPhi

    Is Newton's 3rd law valid in Electrodynamics?

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  41. R

    Can the emission theory of Walter Ritz revolutionize modern physics?

    Hello. I'm supposed to be an electrical engineer but between my ears there is physics! In my sophomore year at Purdue (1964) I got tangled up with the superposition theorem and its lack of shielding between charged particles. I fashioned a model for electrodyamics that included shielding. In...
  42. L

    Suggests topics in Electrodynamics

    Dear All, I have this semester an electrodynamics course, one of our tasks is to write a report topic about any related to the course. Any suggest will be appreciated...Thanks in advance
  43. F

    Methods of Images between two parallel cylinder

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  44. Suman Saha

    Classical Electrodynamics Books | Graduate Level Suggestions

    Friends, can you suggest for some good books which can be studied in graduate level. Except Griffiths, I've completed it.
  45. F

    How to find the charge density given by a Tricky Potential?

    Homework Statement I am trying to solve Problem 2.45 in Electrodynamics by Griffiths, however, my answers were different from those in the book, I am suspect I got a missing step but I could not find it, so here is the Given Problem Find the charge density \rho given by a potential...
  46. chi_rho

    Delta Function Identity in Modern Electrodynamics, Zangwill

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  47. AwesomeTrains

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    Hello everyone! I'm stuck at an Electrodynamics problem and would be happy for some guidance 1. Homework Statement A magnetic dipole \vec{m}(t)=\vec{m}_0cos(\omega t) at the origin can be described by the current density \vec{j}(\vec{r},t)=-\vec{m}(t)\times\vec{\nabla}\delta(\vec{r})...
  48. A

    Electromagnetic induction by a rotating sphere

    Homework Statement http://physics.columbia.edu/files/physics/content/Quals2010Sec2.pdf Problem 1 Consider a rigid, ideally conducting sphere of radius R, with total charge zero. The sphere rotates with angular velocity Ω, ΩR<<c. Suppose a dipole magnetic field threads the sphere. the dipole is...
  49. S

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  50. T

    Electrodynamics Fourier Analysis (Fouriers Trick)

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