# Which way does a compass point in an electromagnetic field with one wire?

Scientists say that the direction of a magnetic field is as follows:

But how can we prove this?

The best way is to use a compass.

From above this would look like the following.

If you plot the ends of a compass's needle around a wire that passes through a piece of paper with direct current through it, you will have the circle above and the direction of flow around the wire.

Do this in several places and you can show rings.

And so you would have the following diagram:

You can do this anywhere along the length of the wire.