某台离心水泵通过调速，转速下降了25%。假设在原转速条件下，扬程为 H，轴功率为N。则调速后的水泵扬程为H1，轴功率N1应为下列哪项？( ) A.H1＝0.30 H，N1＝0.30N B.H1＝0.42 H，N1＝0.27N
A.H1＝0.56 B.N1＝0.42N C.H1＝0.72 D.N1＝0.61N正确答案C
某台离心水泵通过调速，转速下降了25%。假设在原转速条件下，扬程为 H，轴功率为N。则调速后的水泵扬程为H1，轴功率N1应为下列哪项？( ) A.H1＝0.30 H，N1＝0.30N B.H1＝0.42 H，N1＝0.27N
A.H1＝0.56 B.N1＝0.42N C.H1＝0.72 D.N1＝0.61N正确答案C
