## Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)

As the loop falls, there is less magnetic flux going through the loop. By Lenz's law, a current is induced around the loop which opposes the change in flux. Then, the current must produce a magnetic flux in the same direction as the magnetic field $B$. By the right hand rule, this current flows counter-clockwise around the copper loop. As the current flows in the magnetic field, a force on the loop will be created. By the right hand rule, the current flowing across the top of the loop interacting with the magnetic field creates a force on the loop that is directed upward. By the right hand rule, the current flowing along the left side and right side of the loop interacting with the magnetic field create forces on the loop that are directed in opposite directions, so the net force from the current in the sides of the loop is zero. The net magnetic force on the loop is directed upward.