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?
The wires do not have a magnetic pole, however, if the wire was coiled, the magnetic field will be reversed.
Yes, if you switch the sides of the battery in an electromagnet made with a copper wire, you are indeed changing the magnetic poles of the wire.
To understand why, let's first explain how an electromagnet works. When an electric current flows through a wire, a magnetic field is generated around the wire. The direction of this magnetic field follows a specific rule known as the right-hand rule.
The right-hand rule states that, if you hold the wire with your right hand, such that your thumb points in the direction of the current (from positive to negative), then the direction in which the fingers curl around the wire represents the direction of the magnetic field.
Now, in the case of your electromagnet, when you connect the ends of the copper wire to the ends of the battery, current flows through the wire, and a magnetic field is created around it. The end of the wire connected to the positive terminal of the battery becomes the north pole of the magnet, and the end connected to the negative terminal becomes the south pole.
By switching the sides of the battery, you are effectively reversing the direction of the current flowing through the wire. As a result, the magnetic field around the wire also reverses its direction. The end that was previously the north pole now becomes the south pole, and vice versa. So, yes, switching the sides of the battery changes the magnetic poles of the wire.