Transformers have ___________ that are not physically connected to each other.

• A. A coil and a magnet
• B. A single winding
• C. Two windings
• D. A pair of cores

Answer: (C)

Transformers transfer energy between circuits without a direct electrical connection by using two windings that are magnetically coupled through a shared core. The input side (primary) and the output side (secondary) are electrically isolated from each other, so there’s no conducting path between them. When the input current alternates, it creates a changing magnetic flux in the core, and this changing flux induces a proportional voltage in the secondary winding via mutual inductance. This is the fundamental way energy moves from one circuit to another in a transformer. A permanent magnet and a single coil don’t describe how standard transformers operate, and having just one winding or two cores wouldn’t enable the required energy transfer between isolated circuits.