What happens to the force on a conductor if the current or direction of the field is reversed?

When the current in a conductor or the magnetic field it is situated in is reversed, the force acting on the conductor also reverses direction. This phenomenon is due to the relationship defined by Fleming's Left-Hand Rule, which states that if you align your thumb, index finger, and middle finger perpendicular to each other, the thumb represents the direction of the force (motion), the index finger represents the direction of the magnetic field, and the middle finger represents the direction of the current.

When either the current or the magnetic field direction is reversed, this alignment is altered, resulting in the force acting on the conductor being reversed in direction as well. For example, if a conductor experiences a force in one direction when the current flows in a certain direction through a magnetic field, reversing the current or the direction of the field will cause the force to act in the opposite direction.

This principle is fundamental in electromagnetism and underlies the operation of devices such as electric motors, where changing the direction of current or magnetic fields is used to control movement. By understanding this relationship, one can predict how modifications in electrical parameters will affect mechanical motion in various applications.