某工厂为1200kW,C0Sψ=0.65(滞后)的感性负载。为扩大生产,该厂欲添一台同步电动机,额定数据为:PN=500kW,coSψN=0.8(超前),ηN=85%。当同步电动机额定运行时全厂的功率因数为()
A. O.856
B. O.870
C. O.867
D. O.881
我国电力网络目前的平均额定电压主要有()
A. 3.15kV,6.3kV,10.5kV,36.75kV,115.5kV,231kV,346.5kV,525kV
B. 3.15kV,6.3kV,10.5kV,37kV,115kV,231kV,347kV,525kV
C. 3.15kV,6.3kV,10.5kV,37kV,115kV,230kV,345kV,525kV
D. 3.15kV,6.3kV,10.5kV,36.75kV,115.5kV,230kV,345kV,525kV
有一台双绕组变压器变比为110±2x2.5%/11kV,分接头实际接于2.5%挡,其实际变比为()
A. 110/10
B. 110/11
C. 110/10.5
D. 110(1+2.5/100)/11