A.U=220V,I=0.39A | B.U=220V,I=0.55A |
C.U=311V,I=0.55A | D.U=311V,I=0.39A |
U有2 |
R |
PR |
|
A.
| B.
| C.
| D.
|
A.e=Emsinωt | B.e=2Emsinωt |
C.e=2Emsin2ωt | D.e=Emsin2ωt |
A.311V 100Hz | B.220V 100Hz |
C.311V 50Hz | D.220V 50Hz |
A.交变电流的有效值为5
| ||
B.交变电流的周期为0.2s | ||
C.交变电流的频率为50Hz | ||
D.t=0.1s 时线圈磁通量为零 |
2 |
A.最大值是50V | B.频率是50Hz |
C.有效值是50v | D.周期是0.2s |
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