Which among the following type of transformer have smallest size with same electrical specification ?
- A. ONAN type transformer.
- B. Dry type transformer.
- C. ONAF type transformer.
- D. OFWF type transformer.
Answer: D. OFWF type transformer.
Explanation: OFWF (oil-forced, water-forced) cooling is the most effective, so the transformer is the smallest for the same rating.