creating an electric current by moving magnets which changes the magnetic field

creating an electric current by moving magnets which changes the magnetic field

• A. Electromagnet
• B. Electromagnetic induction
• C. Induced magnetic field
• D. Magnetic resonance

Answer: (B)

Electromagnetic induction is the process at work here. When a magnet moves near a conductor (or the flux through a circuit changes in some other way), the magnetic field linking the circuit changes with time. That changing flux induces an electromotive force in accordance with Faraday’s law, and if the circuit is closed, this EMF pushes charges to flow, creating an electric current. The induced current also produces its own magnetic field that acts to oppose the change in the original flux (Lenz’s law). This is exactly how generators work, turning motion into electrical energy. An electromagnet is simply a magnet created by current, not the mechanism for making current from motion. The induced magnetic field is the field produced by the new current, not the cause. Magnetic resonance describes a different phenomenon altogether.

Electromagnetic induction is the process at work here. When a magnet moves near a conductor (or the flux through a circuit changes in some other way), the magnetic field linking the circuit changes with time. That changing flux induces an electromotive force in accordance with Faraday’s law, and if the circuit is closed, this EMF pushes charges to flow, creating an electric current. The induced current also produces its own magnetic field that acts to oppose the change in the original flux (Lenz’s law). This is exactly how generators work, turning motion into electrical energy. An electromagnet is simply a magnet created by current, not the mechanism for making current from motion. The induced magnetic field is the field produced by the new current, not the cause. Magnetic resonance describes a different phenomenon altogether.