# Queries on Maxwell's Equations

1. May 2, 2010

### unseensoul

"Maxwell's equations explain all electromagnetic phenomena." ...What does this mean exactly?

How do these equations represent the unification of electricity and magnetism? What's really an unification? And how can you see it from the equations?

Aren't his equations only applicable to EM waves?

2. May 2, 2010

### cragar

I don’t know if this will answer your question , but he thought what if an electric field could create a magnetic field and so on , This would be a self sustaining electromagnetic field , and this turned out to travel at the speed of light and he knew this was no coincidence , c=1/sqrt(EB) where c is the speed of light and E= is the electrical constant and B is the permeability constant. And another thing this said was that the speed of light was constant to all observers regardless of their motion , this was always in the back of his mind be he kind of ignored it , and later Einstein came along and used this to base relativity on.

3. May 2, 2010

### gabbagabbahey

It means, that classically, any observation involving electromagnetic phenomenon can be explained by Maxwell's equations (actually, you also need the Lorentz force law).

Simple, the source terms for the electric and magnetic fields in Maxwell's equations are electrostatic charge and current densities. Since a current is just moving charges, ll electromagnetic fields (both electric and magnetic) are caused by either stationary or moving charges.

No. They apply to all classical magnetic and electric fields.

4. May 2, 2010

### unseensoul

How can you figure that out from the equations? It's not obvious for me...

5. May 2, 2010

6. May 2, 2010

### unseensoul

I didn't get this last part and how it explains the unification of electricity and magnetism.

Can you give me real life applications (for instance, in electronics) where they apply? Also, what sort of things can be derived from the equations?

7. May 2, 2010