A metal rod PQ rests on two horizontal metal wires that are attached to a battery. The rod lies between the poles of a magnet.
When the switch is closed, the rod moves to the right. What could be changed so that the rod moves to the left?
Open the switch.
Reverse the battery terminals and exchange the poles of the magnet.
Reverse the battery terminals but without exchanging the poles of the magnet.
Turn the metal rod around (P and Q exchanged)
