单项选择题
A.I0=0.3A,P0=160W B.I0=0.6A,P0=160W C.I0=0.15A,P0=240W D.I0=0.6A,P0=240W
A.不变 B.降低 C.增高 D.不能确定
A.2000r/min B.1831r/min C.1739r/min D.1643r/min