I have a magnetic wire and I want to use it to make an electromagnet. The electromagnet will be powered by a 5V, 2A power supply.
How do I know what resistor should I use in series in order to avoid damaging the power supply?
I suppose that I can use Ohm's law, which would mean that I would need a 2.5 Ω resistor. Since the resistance of the wire itself is 0.5 Ω, it means that a 2 Ω resistor would be enough.
I also suppose that if I use a higher resistor, such as 4.7 Ω, the electromagnet would be less powerful.
Am I right, or have I missed something?