Question

In a experiment we did with electromagnets, we used only one battery with a certain voltage and didn't change it out. So did the current stay constant if we used the same battery because the voltage stayed constant????

The purpose of the experiment was to manipulate the number of winds to increase the magnetic field strength.

Thanks

Answer 1

The strength of an electromagnet depends on the electrical current which flows through its wires, but not on what drives that current. The current is measured in the amount of charge per unit time that flows through the wires.

If you hook an electromagnet up to a battery or batteries, the current will be limited by the total electrical resistance around the circuit. Most electromagnets have only small electrical resistances, but if you have many many turns of very thin wire then this resistance may not be that small. Furthermore, you can add a resistor in series with the electromagnet and use it to control the strength of the magnet. If your electromagnet has very little resistance, then the internal resistance of the battery will become the limiting factor. It's very similar to making a short circuit across a battery's terminals and then asking how much current will flow in that short circuit -- it really depends on how well the battery can keep up its voltage while driving large amounts of current.

Hence if the number of turns increased, then the resistance would increase too and the current may not be the same.