变压器空载运行电路中，设变压器为理想器件。若<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251114/23827663_0.png">，则此时（　　）。<br/> <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251114/23827663_0_1.png">