A coil of wire wrapped around an iron core acts as what when it carries current?

When a coil of wire is wrapped around an iron core and carries an electric current, it functions as an electromagnet. This occurs because the flow of electric current through the coil creates a magnetic field, and the presence of the ferromagnetic iron core greatly enhances this magnetic field.

Electromagnets are widely used in various applications, such as electric motors, relays, and magnetic locks, due to their ability to generate a strong magnetic field while allowing the magnetic strength to be controlled by regulating the current. The uniqueness of an electromagnet lies in its transient nature; it only exhibits magnetic properties while current flows through the coil, making it different from permanent magnets which retain their magnetism without needing an electric current.

Understanding this principle is critical for applications in electrical engineering and design, as controlling and utilizing magnetic fields can lead to efficient energy transfer and enhanced functionality in electrical systems.