What type of device is used to transfer electrical energy from one circuit to another?

A transformer is the correct device used to transfer electrical energy from one circuit to another. It operates on the principle of electromagnetic induction, where an alternating current in the primary coil generates a magnetic field, which induces a voltage in the secondary coil. This allows the transformer to either step up or step down voltage levels, efficiently transferring electrical energy without physical connection between the circuits involved.

In contrast, a resistor primarily resists the flow of current, dissipating energy as heat and not transferring energy between circuits. A capacitor stores electrical energy in the form of an electric field and can release that energy, but it does not facilitate the transfer of energy between two separate circuits like a transformer does. An inductor stores energy in a magnetic field when current flows through it, but its primary function is not to transfer energy between circuits, making the transformer uniquely suited for this specific action.