What is required between a magnetic field and a conductor to generate electricity?

• A. Inductance/Inductor
• B. Capacitance
• C. Frequency
• D. Relative motion

Answer: (D)

Electricity is generated when magnetic flux through a conductor changes, and that change comes from relative motion between the conductor and the magnetic field. Move the conductor through a magnetic field, and the field lines cut through the conductor at a changing rate, inducing an electromotive force via Faraday’s law. Inductance is a property of a circuit or a component that stores energy in a magnetic field; capacitance stores energy in an electric field, but neither creates the emf by interacting with a field in this way. Frequency describes how fast the current alternates, not what initiates the generation. So the essential factor is moving the conductor relative to the magnetic field to produce the changing flux that drives the current.