NEIEP Mechanics Practice Exam

If current flows from left to right in a conductor, what is the direction of the magnetic lines of force?

1. Clockwise

2. Counterclockwise

3. Upward

4. Downward

The correct answer is: Counterclockwise

When current flows through a conductor, it generates a magnetic field around it according to the right-hand rule. If you imagine holding the conductor in your right hand with your thumb pointing in the direction of the current (from left to right), your fingers will curl around the conductor. This curling of your fingers represents the direction of the magnetic lines of force. In this scenario, as the current moves from left to right, the magnetic field lines will indeed circulate around the conductor in a counterclockwise direction when viewed from the perspective of looking down the wire with the current flowing away from you. Understanding this right-hand rule is crucial in electrical and magnetic theory, as it helps visualize the relationship between current flow and the resultant magnetic field.