题目7单选题
三相对称负载星形连接时,线电压有效值是相电压有效值的 倍A. <img src="https://tihai-oss-cloud.itihey.com/img/4907182de9e802fa6ed1e949f2299d99.webp">B. 1C. <img src="https://tihai-oss-cloud.itihey.com/img/0bb6e3a9016f9e495ee59960d7d7fc8a.webp">D. <img src="https://tihai-oss-cloud.itihey.com/img/095fcc10479cf84b11a2ac9812d8a982.webp">