Compass And Electric Current

To gain a deeper understanding of what an electric current is and how it behaves in a conductor we can use the water pipe analogy of electricity certainly there are some limitations but they serve as a very basic illustration of current and current flow.

Compass and electric current.

When a compass is placed on one side of the wire it will point in one direction. When you moved the compass near a bar magnet the needle pointed toward the magnet s magnetic field and not toward the north. When the current flows through the wire the compass needle aligns itself with the magnetic field created by the electrons traveling in the current rather than with the earth s magnetic field. A compass will be most affected by the magnetic field of a current carrying wire when the plane of the compass is at 90 degrees to the wire and lest effected when the plane of the compass is in the same plane as the wire.

In either case the compass needle will follow the stronger magnetic field be that the magnet the magnetic field induced by current through the wire or the earth itself. When you put the compass near the electrical wire with current flowing through it the compass did not point north. We can compare the electric current to the water flowing through the pipe. Instead the compass needle pointed in the direction of the current s magnetic field.