A.10Ω B.30Ω C.33Ω D.270Ω
A.大于相线截面积 B.小于相线截面积 C.等于相线截面积
A.22 B.20 C.16 D.10
A.正极电压高于负极电压,且其差值大于“死区电压” B.正极电压小于负极电压 C.正极电压高于负极电压,且其差值小于“死区电压” D.正极电压等于负极电压
A.变极调速 B.改变转差率调速 C.变频调速
A.42 B.48 C.52 D.56