26.
변압기의 전부하 효율을 나타낸 식으로 틀린 것은?
①
\(\frac{\text{변압기용량}\times\text{부하역률}}{\text{변압기용량}\times\text{부하역률}+\text{철손}+\text{동손}}\times100\)
②
\(\frac{\text{변압기출력}}{\text{변압기출력}+\text{무부하손}+\text{부하손}}\times100\)
③
\(\frac{\text{변압기용량}\times\text{부하역률}+\text{부하손}}{\text{변압기용량}\times\text{부하역률}+\text{무부하손}}\times100\)
④
\(\frac{\text{출력}}{\text{출력}+\text{손실}}\times100\)