Question

Krystal is exploring the properties of iron. She takes a large iron nail and finds that the nail does not attract other metal objects. Next, she uses a battery and copper wire to transform the nail into an electromagnet. When she connects the circuit, the nail becomes magnetic and can pick up small metal objects like paper clips. This is shown in the illustration below.
What best describes what has happened to the iron in the nail that causes it to become magnetic?

Answer 1

Explanation:

Iron has tiny magnetic domains inside it. Each domain acts like a tiny magnet with its own magnetic field. These domains are randomly distributed thus resulting in zero magnetic field and iron doesn't behave like a magnet.

When a copper wire is wound around the nail and current is passed through the coil, magnetic field is generated. This magnetic field penetrates through the nail. Due to this the magnetic domains of the nail align in the same direction thus having a net magnetic field. The nail behaves like a magnet till the time current flows through the coil.