What device uses electric current to create a magnetic field?

• A. Permanent Magnet
• B. Electromagnet
• C. Bar Magnet
• D. Lodestone

Answer: (B)

Electric current flowing through a conductor can generate a magnetic field, and a device built to do exactly that is an electromagnet. The coil of wire in an electromagnet produces a magnetic field when current passes through it, and you can change the field strength by adjusting the current or the number of turns in the coil. This is different from magnets like a permanent magnet, a bar magnet, or lodestone, which already have a magnetic field due to the alignment of their internal domains and don’t need an electrical current to produce magnetism. So the best answer is the electromagnet, because it is specifically designed to create magnetism through electric current.