单项选择题
A.1/3MED B.1/4MED C.1/2MED D.3/4MED E.1MED
A.照度不变 B.1/6 C.1/8 D.1/4 E.1/2
A.感抗 B.欧姆损耗 C.容抗 D.介质损耗 E.振荡效应