A 500 KVA transformer has constant losses of 500 W and copper losses at full load is 2000 W. Then at what load is the efficiency maximum?
- A. 125 KVA
- B. 250 KVA
- C. 500 KVA
- D. 1000 KVA
Answer: B. 250 KVA
Explanation: Maximum efficiency occurs when variable copper loss equals constant iron loss. Load fraction k = √(500/2000) = 0.5, giving 0.5 × 500 = 250 kVA.