Symbol of Water
In a magnetic field, any moving particles are forced to spiral along
the magnetic field lines, because they are charged. So, if you create
a circular magnetic field, then plasma particles will be trapped, perpetually
circulating around the loop.
This drawing illustrates this rule.
The red line is a segment of a wire and the arrow designates the direction
of the current, I. The blue circles represent the magnetic field lines,
B, and the arrow heads signify the direction of the magnetic field.
Physicists agree that the magnetic field goes from north to south.
In an electric current any moving charge creates a magnetic field. A
changing magnetic field causes current to flow in a conductor in a closed
circuit. More precisely, a changing magnetic field creates an electric
field and an electric field causes charged particles to move.
the electron and the proton (or other positive ion) were free, they
would simply move in those directions. But they are not free, because
of the magnetic force.
If only magnetic forces were present (no electric field), the proton
would circle around a magnetic field line in the clockwise direction
(from where we are looking) and the electron in the counter-clockwise
direction. These directions are given near the left edge of the drawing.