Final answer:
Electromagnetic induction is the process by which a magnetic field activates voltage in a coil.
Step-by-step explanation:
The process in which a magnetic field activates voltage in a coil is known as electromagnetic induction. When a magnetic field lines cut across a coil of wire, it induces an electric current in the wire. This phenomenon was discovered by Michael Faraday and is one of the fundamental principles in physics.
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