Suppose you make an electromagnet with a copper wire and a battery by putting the two ends of the wire on the two ends of the battery. If you switch the side of the battery, are you changing the magnetic poles of the wire?
Yes, if you switch the battery, you will effectively change the magnetic poles of the wire. To understand why, let's first review how an electromagnet works.
An electromagnet is created by passing an electric current through a coil of wire. When the electric current flows through the wire, it generates a magnetic field around the wire. The direction of the magnetic field depends on the direction of the electric current.
When you connect the two ends of the wire to the two ends of a battery, a current flows through the wire. This current creates a magnetic field with a specific polarity. The side of the wire where the current enters (positive terminal of the battery) is the north pole, and the side where the current exits (negative terminal of the battery) is the south pole. This means that the north pole is formed at one end of the wire and the south pole at the other end.
If you were to switch the battery sides, i.e., connect the positive terminal of the battery to the wire's previous negative terminal and vice versa, the direction of the current would reverse. As a result, the magnetic field generated by the wire would also change. The north and south poles would flip, and the side that was previously the north pole would become the south pole, while the side that was previously the south pole would become the north pole.
So, by switching the battery sides and reversing the direction of the current, you effectively change the magnetic poles of the wire.