更多"[单选题](Lc5A2113).电压的瞬时值表达式为u＝110sin("的相关试题:
[单选题]
已知工频电压有效值和初始值均为380V，则该电压的
瞬时值表达式为（）。
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[单选题]某正弦电压有效值为380V,频率为50Hz,计时起始数值等于380V,其瞬时值表达式为():
A.u=537sin314t
B.u=537sin(314t+450)
C.u=380sin(314t+900)
D.u=380sin(314t-900)
[单选题]已知正弦电压的有效值为380V，初相角为一120。，角频率为314r／s，其瞬时值表达式为（ ）。
A.u=380√2sin（314t一120。）v
B.u=380√3sin（314t一120。）v
C.u=380√2sin（314t+120。）v
D.u=380√3sin（314t+120。）v
[单选题]电压的瞬时值表达式为：u=220sin（ωt-π/3）V，下面（）答案是正确的。
A.电压有效值为220V，相位角是π/3
B.电压有效值为220/√2V，相位角是（ωt-π/3）
C.电压有效值为220/√2V，相位角是-π/3
D.电压有效值为220√2V，相位角是π/3
[判断题](La5B1021).已知一个正弦电压的瞬时值表达式为u＝500sin(ωt＋π／2)V，则其复数形式为u＝500∠90°( )
A.正确
B.错误
[单选题] 电压和电流的瞬时值表达式分别为u=220sin(ωt-10°)和i=5sin(ωt-40°),那么( )。
A.电流滞后电压40°;
B.电流滞后电压30°;
C.电压超前电流50°;
D.电压超前电流30°。
[单选题]已知一正弦电动势的最大值为220V，频率为50Hz，初相位为30。，此电动势的瞬时值表达式是（ ）。
A.e=220sin（314t+30°）v
B.e=220√2sin（314t+30°）v
C.e=220Sin（314t一30°）v
D.e=220√2sin（314t一30°）v
[判断题]正弦交流电流的最大值为50A，初相角为π/3，其瞬时值表达式为ｉ＝50sin(ωt+π/3)。
A.正确
B.错误
[判断题]纯电感正弦交流电路中的瞬时功率等于电流瞬时值与电压瞬时值的乘积
A.正确
B.错误
[单选题]电流电压瞬时值的表达式分别为：u=220sin(wt-100)V,i=5sin(wt-400)A,那么（ ）
A.电流滞后电压400
B.电流滞后电压300
C.电压超前电流500
[单选题]在交流电路中，电压瞬时值和电流瞬时值的乘积叫做（）
A.平均功率
B.总功率
C.瞬时功率
D.以上都错
[单选题]电力系统中任一高次谐波的瞬时值不得超过同相基波电压瞬时值的（ ）。
A.1%
B.2%
C.5%
D.10%
[单选题]1.183. 第183题
有两个正弦量,其瞬时值的表达式分别为:u=220sin(Ωt-10°),i=5sin(Ωt-40°),可见,( )。
A.电流滞后电压40°
B.电流滞后电压30°
C.电压超前电流50°
D.电流超前电压30°
[单选题]4.110. 第110题
有两个正弦量,其瞬时值的表达式分别为:u=220sin(ωt-10°),i=5sin(ωt-40°),可见,()。
A.电流滞后电压30°
B.电压超前电流50°
C.电流滞后电压40°
D.电流超前电压30°
[单选题](Lb5A2031).交流电路中，电压瞬时值与电流瞬时值乘积称为( )
A.有功功率
B.视在功率
C.瞬时功率
D.功率
[判断题]电力系统中任一高次谐波的瞬时值不得超过同相基波电压瞬时值的5%。（ ）
A.正确
B.错误
[单选题]有两个正弦量,其瞬时值的表达式分别为u=220sin(ωt-10°)V,i=5sin(ωt-40°)A。那么( )。
A.电压滞后电流30°
B.电压滞后电流50°
C.电流滞后电压30°
D.电流滞后电压40°
