Electromagnetism Definition and 853 Threads

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. D

    Understanding Electromagnetism: Clearing Up Concepts and Interactions

    I need to clear few concepts regarding electromagnetism so please help me...my question is let's say a hypothetical particle with a positive charge interacts with a negative particle with the same amount of charge, what will happen to their electromagnetic field? will it get neutralized...
  2. T

    Question about electromagnetism

    Hi Can the magnet so placed in an environment that is causing the rotation? tnx. :confused:
  3. C

    Capacitance and Electromagnetism

    1.Suppose that a blood vessel is 2.5 mm in diameter, the magnetic field is 0.08 T, and the electromagnetic force is 0.10 mV. What is the velocity flow of the blood? Assume that blood carries charged ions. Homework Equations B=F/qvattempt looking for v isn't possible since I have no idea how to...
  4. C

    Electromagnetism qs need someone to check my work

    Homework Statement An electron is accelerated horizontally from rest in a television picture tube by a potential difference of 10,000 V. It then passes between two horizontal plates 5.0 cm long and 1.0 cm apart which have a potential difference of 200 V. At what angle θ will the electron be...
  5. T

    Exploring Electric Circuits in Electromagnetism

    Hi, I'm studying this electric circuits in electromagnetism now, and I never studied this before, so my questions probably have very simple answers :P. So, if there is a battery generating an electric field between its plates, there is a potential difference between the plates. If the...
  6. J

    Is the strong/weak force infinite like electromagnetism

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  7. C

    Calculating the Angle of an Electron Passing Between Charged Plates

    Homework Statement An electron is accelerated horizontally from rest in a television picture tube by a potential difference of 10,000 V. It then passes between two horizontal plates 5.0 cm long and 1.0 cm apart which have a potential difference of 200 V. At what angle θ will the electron...
  8. J

    Electromagnetism / Laplaces Equation

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  9. S

    How Does Energy Density Depend on Distance for Normal Incidence?

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  10. S

    How Does Energy Density Vary with Normal Incidence in Non-Magnetic Materials?

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  11. B

    Physics Test Question, Electromagnetism (induced charges) (grade 12)

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  12. C

    Help to explain electromagnetism, a loop of wire in a magnetic field.

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  13. Y

    Electromagnetism learning problem

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  14. K

    How Quickly Can an MRI's Magnetic Field Be Safely Altered?

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  15. M

    Who discovered electromagnetism before Øersted but dismissed it?

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  16. S

    Potentials in classical electromagnetism

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  17. M

    Help understanding electromagnetism (fields and radiation)?

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  18. M

    Electromagnetism used to determine chemical mixtures?

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  19. G

    Electromagnetism: Questions About Energy Density

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  20. B

    Electromagnetism: cylindrical or rectangular coordinates.

    Hi. Sorry my spelling, because I am not English. Homework Statement In a sphere truncated sector with an angle of 60 degrees, there is a uniform charge distribution, \rho. Calculate the electric field in (0,0,0). The sector starts in z=a and ends in z = b. The sphere center is in (0,0,0)...
  21. K

    Application of Electromagnetism question

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  22. D

    Electromagnetism - Find length of coil

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  23. S

    How Does Charge Distribution Affect Potential in Electromagnetic Fields?

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  24. A

    Electromagnetism and Light Questions

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  25. R

    Exploring Electromagnetism: A Non-Mathematical Approach

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  26. F

    Electromagnetism Book Recommendations

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  27. K

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  28. R

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  29. X

    Calculating Angular Momentum of a Monopole-Charge System

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  30. D

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  31. mrspeedybob

    Help me understand electromagnetism.

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  32. R

    Where's the Photon in Electromagnetism?

    While light's photon is manifested where's the photon in electromagnetic radiation? Does it show up in some materials? Thanks
  33. L

    Electromagnetism linear charge density question

    Homework Statement Two rods, of lengths l1 and l2, have charges q1 and q2 a)Find the charges per unit length for each rod individually. b)Find the charge per unit length, averaged over both rods. c)Check your result for l1 approaching 0 d)Check your result for l1=l2 Homework...
  34. G

    Electromagnetism in Reference Frames

    If observer A was at rest with respect to a charge that was moving with a constant velocity |v| > 0 in observer B's reference frame, would observer A detect a magnetic field?
  35. T

    How to Measure and Create Capacitors with Basic Materials?

    Hi everyone, I'm trying to solve this prac design, but still don't know what to do, can anyone please give me some suggestions? You are given an old cardboard box from Faraday’s, the bargain supermarket for electrical enthusiasts (“Everyday Low Charges”). The box contains  a battery, ...
  36. MathematicalPhysicist

    Electromagnetism of particle problem

    Homework Statement We are given surface current density, K which is constant (K is negative) along the z-axis which is placed in x=a plane (the board which contains this density is neutral), in x=0 plane there's an infinite plane which is charged by a surface density \sigma which is constant...
  37. E

    The magnetic component of electromagnetism

    May a magnetic field exist w/o electricity? Yes, as lodestone shows us but where is the electricity? Electricity generates magnetism with it. So where is the electricity with lodestone?
  38. V

    Are My Calculations on Electromagnetism Vectors Correct?

    n.b: The following is all math problems, dealing with vectors, I just need someone to check I'm doing the cross products and dot products properly< thank you! :) ---- The electric field exerts a force per unit charge: \bf{E} = (\hat{x} - 2\hat{y} + 4\hat{z}). i) What is the magnitude of E...
  39. W

    Which Book is the Best for Learning Electromagnetism?

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  40. G

    Need help with a electromagnetism question

    A stone is moving constantly in a horizontal motion in a uniform magnetic field in the direction pointing into the page. The field's strength is 1.7T. How fast does the stone have to move in order for it to remain moving horizontally without any vertical deviation? For this quesion, using...
  41. I

    E=d/dt(NBAcostθ) Magnetic Field Induced by Rotating Wire in Uniform Field

    Homework Statement A 20 turn wire that has a surface of 400cm^2 is rotating around an axe and is at a right angle to a uniform magnetic field of 0.3T. Find the average magnetic field induced if the speed of the rotation is 10 rotations/second. Homework Equations Faraday's Law...
  42. L

    How Do Virtual Photons Influence the Range of Electromagnetic Interactions?

    In a particle physics formalism, electromagnetism can be described in terms of interchange of virtual photons. The range is then c.t = hbar / E with t the lifetime, and E the energy of the virtual particle. What is the argument then, for long range EM interactions, in terms of E? Is it...
  43. B

    How Does a Charged Particle Behave in a Magnetic Field?

    1. A particle of charge q=6E-6C and mass m=1E-10kg is fired out of a charge gun towards the uniform magnetic field pointing into the page, B=0.50T. The particle moves vertically up originally and then accelerated through potential difference of 200V. There is a diagram of the B field going...
  44. T

    Harmonic average and electromagnetism

    We know that a lot of electrical components associations are calculated using the harmonic average. If we have parallel resistors we use the harmonic average. If we have serial capacitors we use the harmonic average too and so on... But my question is: why the harmonic average? what does...
  45. N

    Classical Electromagnetism vs. 3rd Law? (second round: Relativity)

    Ouch, had just written a big post when my university internet connection timed out on posting, so I'll keep this one short but powerful: I came to the understanding E and B fields are modified when changing reference frames. But what about the following situation: Charge q (named 1) is...
  46. L

    Electromagnetism and earth question

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  47. P

    Electromagnetism questions - polarisations and waveguides

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  48. O

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  49. M

    Messenger photon in electromagnetism intractions

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  50. K

    Introduction to electromagnetism - Maxwell's equations

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