A.I=U/R B.I=(U-E./R C.I=(E-U)/R D.I=E/R
A.n=U/CEΦ-(R/CECTΦ2)T B.n=U/CEΦ C.n=U/CEΦ-RI/CEΦ D.n=-(R/CECTΦ2)T
A.减小励磁电流 B.电枢串联电阻 C.减小电源电压 D.改变磁极对数