A synchronous generator has a synchronous speed of 1000rpm and 6 poles. The frequency of the generator is ( ) 。
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The symbol and units of measurement for ACTIVE power are ( )。
A. S, W
B. Q, VA
C. P, VA
D. P, W
The long line model of a transmission line should be used when( )。
A. Line length less than 80 km.
B. Line length between 80 km and 250 km.
C. Line length longer than 250 km.
AC resistance is higher than DC resistance due to( )。
A. Core loss
B. Skin effect
C. Hysteresis
D. Eddy currents
某保护用电流互感器的准确级为10P25级,即只要流过电流互感器一次侧的短路电流不超过其额定一次电流倍,其最大复合误差不会超过。( )
A. 25、10%
B. 10、25%
C. 25、25%
D. 10、10%
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