What is the primary purpose of oil in a transformer?

The primary purpose of oil in a transformer is to cool and insulate the coils. Transformer oil acts as both a coolant and an insulating medium. During operation, electrical energy produces heat in the transformer's windings due to resistance. The oil circulates through the transformer, absorbing heat from the coils and dissipating it to maintain optimal operating temperatures, thereby preventing overheating. Additionally, the oil provides electrical insulation between various components, such as the windings and the metallic tank. This insulation is crucial for ensuring safe operation and preventing electrical breakdown.

The other options do not accurately represent the function of oil in a transformer. While enhancing conductivity is essential in electrical systems, oil does not enhance conductivity; rather, it serves as an insulator. Generating electricity is the role of the transformer itself through electromagnetic induction, not the oil used within it. Lastly, while reducing friction is relevant in mechanisms with moving parts, it is not pertinent to the function of oil in a transformer, as transformers primarily rely on electrical components without mechanical movement that would require lubrication.