What's the core difference between the electric and magnetic forces?

Question

I require only a simple answer. One sentence is enough... (It's for high school physics)

Answer 1

Electric forces are created by and act on, both moving and stationary charges; while magnetic forces are created by and act on only moving charges.

Answer 2

Electric monopoles exist. Magnetic monopoles don't^* exist.

This is the reason that Maxwell's laws governing electricity and magnetism aren't symmetric. Maxwell's laws say that $\nabla \cdot B = 0$ and $\nabla \cdot E = 4\pi\rho_{e}$, but if magnetic monopoles existed this would be $\nabla \cdot B = 4\pi\rho_{m}$ and $\nabla \cdot E = 4\pi\rho_{e}$. A similar asymmetry in induction would be corrected.

The experimental lack of evidence for magnetic monopoles can then be taken as the main reason we distinguish between the two forces.

_*(Probably.)

Answer 3

For the purposes of high school physics it is reasonable to say that electric fields start and stop on charges but magnetic fields always run in loops.

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This fails to be rigorous in at least two ways:

• Relative velocity mixes the two types of fields in a manner governed by the Lorentz transform, so the truth is like wsc says.
• It is an open question if there exist any magnetic monopoles, but theoretical prejudice favors their existence for reasons of beauty.

Answer 4

Consult this document by Hans de Vries:

The simplest, and the full derivation of Magnetism as a Relativistic side efect of ElectroStatics

He uses only Electrostactic field and the non-simultaneity to derive the Magnetic Field.

It appears that the Magnetic field is a side effect of movement of charges in the electric field.

If we pretend that the magnetic field exists beyond a mere artifact then the following question must be answered: How can the particles communicate information about its position and velocity so that, in the past, they can adjust the source of the electromagnetic energy?

(*) Hans de Vries has a very interesting online book (not yet finished) in his site.

added:

Magnetic forces are induced by the motion and, much like Coriolis force, is not a real force. ...

wikipedia ..the Coriolis effect is an apparent deflection of moving objects when they are viewed from a rotating reference frame. (a moving frame induces forces, there is no need to be a rotating one)

ps: it is frustating to be down voted without a comment :( it´s an injustice......yes it is - Calimero.

Answer 5

Not to be slick, but starting with Hans Christian Ørsted, then on through James Clerk Maxwell and Albert Einstein we time and again reinforce that there is none -- they are heads and tails of the same coin.

Answer 6

Unlike electric fields, magnetic fields do no work on charges.

Answer 7

Magnetic forces are always normal to the direction of the velocity of the charge it acts upon, whereas electric force are independent of the direction the charge moves in.

Answer 8

Electric fields are divergent, magnetic fields are convergent.

Why the downvote? Anyone?

Answer 9

Electric forces act between charged bodies (charges), magnetic forces act between magnetized bodies (magnets). The latter can be said differently: magnetic forces act between currents of neutralized charges.