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[单选题]
已知某正弦交流电的频率为50Hz,有效值相量为U=20∠30°V,则其瞬时表达式为()
A.u=20sin(50t+30°)V
B.u=20sin(314t+30°)V
C.u=28.28sin(50t+30°)V
D.u=28.28sin(314t+30°)V
![](https://static.youtibao.com/asksite/comm/h5/images/m_q_a.png)
D、u=28.28sin(314t+30°)V
![](https://static.youtibao.com/asksite/comm/h5/images/solist_ts.png)
A.u=20sin(50t+30°)V
B.u=20sin(314t+30°)V
C.u=28.28sin(50t+30°)V
D.u=28.28sin(314t+30°)V
D、u=28.28sin(314t+30°)V
A.i=10√2Sin(50t+30°)A
B.i=10Sin(314t-30°)A
C.i=10√2Sin(314t-30°)A
D.i=10Sin(314t+30°)A