Which statement best describes the function of insulating fluid in relation to the core and coil assembly?

• A. To insulate and to cool
• B. To lubricate
• C. To seal
• D. To color

Answer: (A)

Insulating fluid around the core and windings serves two main jobs: it provides dielectric insulation to prevent electrical arcing between conductors and the core, and it acts as a coolant to carry away heat generated in the windings. This combination allows the transformer to operate at higher voltages safely while keeping temperatures within limits. Lubrication, sealing, or coloring are not the primary roles of this fluid in the core-and-coil region, so those options don’t describe its main function here.