Wound and Shell are the two types of ______

• A. Transformer core configurations
• B. Winding arrangements
• C. Core laminations
• D. Insulation classes

Answer: (A)

The idea being tested is how transformer cores are classified by their magnetic structure. Wound and Shell describe two core configurations used in transformers.

In a core-type transformer, the windings typically surround a laminated core that has two or three vertical limbs, forming a rectangular frame. The magnetic path runs through the core pieces, and the windings sit on or around the core limbs.

In a shell-type transformer, the core partially surrounds the windings, with windings placed on a central limb and the surrounding core forming a shell around them. This style concentrates flux in the central limb and tends to give a more compact, rigid construction with different leakage characteristics.

Other options refer to different aspects: winding arrangements deal with how windings are laid out or connected, core laminations describe the material and its layering to reduce eddy currents, and insulation classes relate to temperature ratings and insulation materials.

So, Wound and Shell are two transformer core configurations.