Why do we get shocks from electric current, but not from magnetic fields?

212 views

[ad_1]

We’re told that magnetism and electricity arise from the same source, but they behave very differently IRL. Magnetic force can be felt at a distance without a medium, but only as an attraction or repulsion. Electric potential needs a conductor of some kind, ionized air molecules at the least–and when it arrives, it can do a lot of damage! I’d love a simple explanation of how they differ and how they are linked.

In: Physics
[ad_2]

There are no magnetic monopoles. In order for a magnetic field to exist, there must be both a source, and sink. That is the fundamental asymmetry in Maxwell’s Equations.

A shock is the motion of electrons through the body. Magnetism does not, on its own, cause charges to move. Only moving charges interact with magnetic fields.

This means that moving a magnet past your hand will create current flow, but simply having one will not.

Logically, this would indicate that the handling and movement of magnets should cause shocks. In fact, it technically does, *but* they are so immensely small as to be effectively nonexistent. The electrical motion produced by moving magnets only becomes significant when chained together in a way that amplifies it, such as in large coils of wire. This is how generators work.

Electric currents and electric fields are distinctly different. The electric field has a potential difference which pushes the charges, but the damage being done to you is caused by the movement of the electrons not just the electric field

That said, you can interact with the electric field. Rub a balloon on your head and watch it lift your hair up, that’s the effect of the electric field.

Static magnetic fields are less exciting than moving ones but you deal with static ones regularly with fridge magnets but you can also use electromagnets to make stupidly strong static magnetic fields [and use them to levitate a frog](https://www.youtube.com/watch?v=KlJsVqc0ywM).

Changing magnetic fields are more interesting because they can induce currents. You generally only encounter alternating magnetic fields transformers and wireless charger. If you were exposed to a strong enough alternating magnetic field it would induce an electric current in you and shock you, but it’ll probably launch you like a coilgun first so ehh