What device allows the transfer of electric energy between two circuits that are completely insulated from each other through magnetic induction?

What device allows the transfer of electric energy between two circuits that are completely insulated from each other through magnetic induction?

• A. Capacitors
• B. Inductors
• C. Transformers
• D. Resistors

Answer: (C)

Transferring electrical energy between two circuits that are electrically isolated is done with a transformer. When alternating current flows in the primary winding, it creates a changing magnetic flux in the core. This changing flux links to the secondary winding and induces a voltage in it. Because the two windings are magnetically coupled but electrically separated, energy moves from the primary to the secondary without a direct electrical connection, giving galvanic isolation while allowing voltage or current to be transformed based on the turns ratio. Capacitors transfer energy through electric fields between plates and across a dielectric, not by magnetic induction, so they don’t accomplish energy transfer between isolated circuits via induction. Inductors store energy in their magnetic field, but a single inductor doesn’t transfer energy to another circuit unless you have a second coil nearby; a transformer is the purpose-built two-coil system that enables efficient, isolated energy transfer. Resistors simply dissipate energy as heat and don’t serve to transfer energy between isolated circuits.

Transferring electrical energy between two circuits that are electrically isolated is done with a transformer. When alternating current flows in the primary winding, it creates a changing magnetic flux in the core. This changing flux links to the secondary winding and induces a voltage in it. Because the two windings are magnetically coupled but electrically separated, energy moves from the primary to the secondary without a direct electrical connection, giving galvanic isolation while allowing voltage or current to be transformed based on the turns ratio.

Capacitors transfer energy through electric fields between plates and across a dielectric, not by magnetic induction, so they don’t accomplish energy transfer between isolated circuits via induction. Inductors store energy in their magnetic field, but a single inductor doesn’t transfer energy to another circuit unless you have a second coil nearby; a transformer is the purpose-built two-coil system that enables efficient, isolated energy transfer. Resistors simply dissipate energy as heat and don’t serve to transfer energy between isolated circuits.