Which device uses electric current to create a magnetic field?

Which device uses electric current to create a magnetic field?

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

Answer: (B)

When electric current flows through a conductor, it creates a magnetic field around it. Turning that idea into a usable device, wrapping the wire into a coil and adding a magnetic core concentrates and strengthens the field, and crucially allows it to be turned on and off by changing the current. That controllable, current-driven magnetic field is what defines an electromagnet. Permanent magnets and bar magnets generate magnetic fields without any electrical current—these are magnetized materials, not devices powered by electricity. A solenoid is a coil that produces a magnetic field when current runs through it, but as a component, it’s the basic building block rather than the complete device whose primary purpose is to provide a controllable magnetic field.

When electric current flows through a conductor, it creates a magnetic field around it. Turning that idea into a usable device, wrapping the wire into a coil and adding a magnetic core concentrates and strengthens the field, and crucially allows it to be turned on and off by changing the current. That controllable, current-driven magnetic field is what defines an electromagnet. Permanent magnets and bar magnets generate magnetic fields without any electrical current—these are magnetized materials, not devices powered by electricity. A solenoid is a coil that produces a magnetic field when current runs through it, but as a component, it’s the basic building block rather than the complete device whose primary purpose is to provide a controllable magnetic field.