A.QBN1-25D B.QBN2-25D C.QBZ1-25D D.QBZ2-25D
A.瞬時(shí)功率與視在功率之比B.有功功率與視在功率之比C.電路的總電壓與總電流相位差的余弦D.電路的電壓與電流相位差的正弦
A.220V B.380V C.√2×220V D.√3×220V