Is there a magnetic field around a moving single charge?

In summary, according to the speaker, a magnetic field would be created if you moved a group of charged particles. This is because the electrons are moving in one direction while the protons are moving in another.
  • #1
lenfromkits
107
0
is there a magnetic field around a moving "single" charge?

Quote: "All moving charged particles produce magnetic fields."

Hypothetically - if you took a bunch of charged hydrogen ions (H+) and moved them through space, would there be a magnetic field around them? (ie, there are no electrons anywhere in this experiment, only protons)

From what I understand, a magnetic field only occurs when you have electrons amidst the positively charge protons such that - relatively speaking - in the case of a current, the electrons are moving one direction while the protons move the other.

Is there anywhere I can find information about this specific test?

Thanks!
:)
 
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  • #2


Yes, there would be a magnetic field around an isolated moving charge.
 
  • #3


Consider that current - an element of Maxwell's equations for electromagnetism - is measured as charge-per-unit-time, moving across an arbitrary boundary.

The nature of the current-bearing elements don't matter. Protons are fine, or alpha particles (helium nuclei +2) they make a dandy magnetic current as they dash off.
 
  • #4


It certainly makes a magnetic field. An easy way to prove this is that under a Lorentz transformation, a pure electric field becomes a mixture of electric and magnetic fields.

What you have to watch out for is the assumption that this is "the" field of an infinitesimal element of current. Maxwell's equations imply charge conservation, but an isolated infinitesimal element of current violates charge conservation.
 
  • #5


bcrowell said:
It certainly makes a magnetic field. An easy way to prove this is that under a Lorentz transformation, a pure electric field becomes a mixture of electric and magnetic fields.

What you have to watch out for is the assumption that this is "the" field of an infinitesimal element of current. Maxwell's equations imply charge conservation, but an isolated infinitesimal element of current violates charge conservation.

Oooh! Whenever someone thinks like me, it's a clear sign of brilliance, I figure.

There aren't many examples of discussing electrostatics, so I'd started a thread called Postulate: EVERY field has a "magnetic" equivalent. under General Relativity,
and you'll see my cleverness is only rivaled by my humility. And modesty.

Anyhow, I agree thoroughly that electricity and magnetism are a unity with apparent differences, due principally to our frames of reference.
 

1. What is a magnetic field?

A magnetic field is a force field that is created by moving electric charges. It is responsible for the force of attraction or repulsion between two magnets, and is also responsible for the behavior of moving electric charges in the presence of a magnet.

2. How is a magnetic field created?

A magnetic field is created when a moving electric charge, such as an electron, creates a circular or helical path around itself. This creates a force field that can attract or repel other moving electric charges.

3. Is there a magnetic field around a stationary electric charge?

No, a magnetic field is only created by a moving electric charge. A stationary electric charge does not create a magnetic field, but it can interact with an existing magnetic field.

4. Does the strength of the magnetic field depend on the speed of the moving charge?

Yes, the strength of the magnetic field around a moving charge is directly proportional to the speed of the charge. As the speed increases, the strength of the magnetic field also increases.

5. Can a magnetic field be shielded or cancelled out?

Yes, a magnetic field can be shielded or cancelled out by using materials that are not affected by magnetic fields, such as mu-metal or superconductors. Additionally, two magnetic fields can cancel each other out if they are moving in opposite directions with the same strength.

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