More Examples Direction of Current Flow Look at the top part of the illustration provided here (A.) In this illustration we see a current-carrying conductor. We can easily show the direction of the current by an arrow. We can also show the direction of the magnetic field. If you are looking at the cross-section of the conductor, how would you indicate the direction of current flow in the conductor in a diagram? We use a widely accepted convention to do this.

In the figure provided here, look at the middle diagram (labeled B.) This diagram is showing the cross-section of a conductor which is surrounded by a magnetic field. The innermost circle represents the cross-section of the conductor. Other circles are indicating the presence of a magnetic field. In this sketch, the current is flowing “toward” the observer. This is indicated by the “dot” at the center of the circle. Notice the direction of the magnetic field if the current is flowing toward the observer – it is clockwise.

Now look at the lower part of the figure (C.) In this figure we are showing the current to be flowing “away” from the observer. This is indicated by the “+” sign at the center of the circle. Notice the direction of the magnetic field. Now it is oriented in counterclockwise manner.

Sources:
1. Physics for Technicians - A Systems Approach. Pub: John Wiley & Sons

2. Naval Electrical Engineering Training Series