What is the term for the phenomenon where a changing current in one coil induces current in a nearby coil without a direct connection?

What is the term for the phenomenon where a changing current in one coil induces current in a nearby coil without a direct connection?

• A. Mutual induction
• B. Self induction
• C. Capacitive coupling
• D. Electrical coupling

Answer: (A)

Mutual induction occurs when a changing current in one coil produces a changing magnetic field that links with a nearby coil, inducing a voltage in the second coil. According to Faraday's law, the induced EMF is proportional to the rate of change of the linked magnetic flux, and the current in the second coil will flow if its circuit is closed. This magnetic coupling is what allows energy transfer between windings without a direct electrical connection, as in transformers. This is different from self-induction, where the EMF is generated in the same coil that carries the changing current due to its own changing magnetic field. Capacitive coupling involves energy transfer through the electric field between conductors, not magnetic linkage, and is typically relevant under different conditions (such as high frequency or close spacing). The term electrical coupling is too vague for this specific magnetic interaction.

Mutual induction occurs when a changing current in one coil produces a changing magnetic field that links with a nearby coil, inducing a voltage in the second coil. According to Faraday's law, the induced EMF is proportional to the rate of change of the linked magnetic flux, and the current in the second coil will flow if its circuit is closed. This magnetic coupling is what allows energy transfer between windings without a direct electrical connection, as in transformers.

This is different from self-induction, where the EMF is generated in the same coil that carries the changing current due to its own changing magnetic field. Capacitive coupling involves energy transfer through the electric field between conductors, not magnetic linkage, and is typically relevant under different conditions (such as high frequency or close spacing). The term electrical coupling is too vague for this specific magnetic interaction.