Video narration
Can electricity turn a compass needle without touching it? You've seen a magnet make a compass needle swing; now imagine placing a wire nearby instead. Place the compass beside the wire, in a position where its needle can turn. With no current flowing, the needle stays still. But connect the wire so electric current flows, and the needle turns. The wire isn't pushing it. The current itself creates a magnetic field around the wire, and the compass responds to it. You cannot see the field, but you can see its effect. Now reverse the current's direction. The magnetic field reverses too, so the compass needle turns the other way. Switching the current on makes the needle move; reversing it changes which way it points. Yes, a current-carrying wire creates a magnetic field, and that field can turn a nearby compass needle.