Can anyone explain Maxwell's 4 equations in simple terms, which even a middle school kid can understand?

Question

I have been looking for a simple explanation for Maxwell's 4 Equations, with examples to elucidate (all my life) and I haven't found a satisdfactory one yet. Can you help?

Answer 1

I'll try.

The first equation basically say that is you look at an electric field entering a volume, like a box, and you look at it leaving the volume, any difference in its strength is due to thae amount of electrical charge inside the volume. So if there is no charge present, the electric field will not change value. Another way to look at this is if there is a charge in the volume, there will be an electric field present outside the voulme due to the charge. So the first equation relates charge to electric field strength.

The second equation involving the electric field is a bit more esoteric. It says that unless there is a magnetic field that changes strength over time, the electric field doesn't curve around itself, that is, it always begins and ends on an electric charge. If there is a time varying magnetic field that is coupled to the electric field by moving charges, then the second equation says the electric field can loop back on itself.

The third equation is like the first equation except for the magnetic field, and it says that there is no "magnetic charge" or magentic monopoles. Magnetic fields are associated with moving electric charges and the fields do not terminate on teh moving charges. So the third equation just says that there is no such thing as a magenitc charge.

The fourth equation says a couple of things. For the case where teh magnetic field is not changing in time, it says that the magentic field makes closed loops around the moving charge that generates the field. If you think of current flowing through a wire, then the magnetic field would look like circles centered on the wire and plane described by these circles would be perpendicular to the wire. If the field varies in time, then another term is added to the equation which says there is a time varying electric field that is also giving rise (or fighting) the magnetic field. This term is called the displacement current andis Maxwell's contribution.

The displacement current was his idea to try to unify the four different equations. And it works.

Hope this helps.

Answer 2

a=b c=d e=f
abc*def=s/h