What is the magnet called that is formed by passing current through a coil of wire wound on a soft iron core?

• A. Permanent magnet
• B. Electrostatic magnet
• C. Temporary magnet
• D. Electromagnet

Answer: (D)

An electromagnet is formed when current flows through a coil of wire wound around a soft iron core. The electric current creates a magnetic field in the coil, and the soft iron core provides a low-reluctance path that concentrates and strengthens that field, making a strong magnet. Because its magnetism exists only while current is flowing, it’s distinct from a permanent magnet, which stays magnetized without any current. The term “electrostatic magnet” isn’t a standard concept in magnetics, and while a piece of iron can become magnetized temporarily in a magnetic field, the device described—which relies on current through a coil to produce magnetism—is specifically called an electromagnet.