Question

What is the liquid in transformers?

• A. Heavy water
• B. Mineral oil
• C. Distilled water
• D. Toluene

Answer 1

The correct option is B

Mineral oil

1. Mineral oil is a filled-in transformer.
2. The chemical and electric needs of a transformer can be fulfilled by mineral oil.
3. The purpose of mineral oil is used for cooling, insulation for windings, and prevention of cellulose from oxidation.
4. There are two types of mineral oil, Paraffin-based, and Naptha based although the paraffin oil is of better quality.

Hence, option (B) is the correct answer.