Polarity is determined by the direction the __________ coil is wrapped in relation to the direction to the other coil

• A. Primary
• B. Secondary
• C. Core
• D. Shield

Answer: (B)

Polarity in a transformer is set by how the windings are oriented relative to each other. The magnetic flux in the core links both windings, and the sign of the secondary voltage depends on the direction the turns are wound around the core. If the secondary is wound in the same sense as the primary, the ends that correspond to the same reference point will have voltages that are in phase with each other. If the secondary is wound in the opposite sense, its polarity is inverted. This arrangement is often described with the dot convention: ends marked as dots share the same instantaneous polarity when voltages are developed.

The core simply provides a magnetic path and does not determine polarity, and the shield has no role in setting polarity. Therefore, the polarity is determined by the direction of the secondary coil relative to the primary.