Correct Answer : Option (D) : Both cooling and Insulation
Explanation : Transformers have broad applications for various industries; mainly, distribution transformers are filled with oil. The two-primary function of the transformer oil is given below
Coolant : As we know, the transformer's coils are made up of copper and carrying a very high current, so it becomes hot in a very short time. The transformer oil is a good conductor of electricity and heat, so it reduces the coil's temperature.
Insulator : The transformer oil has high dielectric strength; it means it can withstand very high voltage; this is the only reason it acts as an insulator in the transformer
