Which list correctly identifies the three main components of transformers?

• A. Core, Windings, Insulating Fluid
• B. Core, Windings, External Lightning Arrestor
• C. Laminations, Core, Insulating Fluid
• D. Windings, Insulating Fluid, Lightning Arrestor

Answer: (A)

The three essential internal parts are the core, the windings, and the insulating fluid. The core provides a low-reluctance path for magnetic flux and is typically made of laminated steel to reduce energy losses. The windings are the primary and secondary coils that enable energy transfer through inductive coupling, allowing voltage to be transformed. The insulating fluid surrounds and insulates the windings while also transferring heat away to prevent overheating in oil-filled transformers.

Other items listed aren’t part of the transformer's main internal structure. A lightning arrestor is protective equipment used to divert surge energy, not a core component of the transformer itself. Laminations are a detail of the core construction, not a separate main component.