.已知某正弦电压的频率f=50Hz,初相角φ=30°,有效值为100V,则其瞬时表达式 可为 (   )。

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69437' and id < 4496822 and id<>'4496822' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku_ where sourceid='69437' and id > 4496822 and id<>'4496822' order by id asc limit 5