A.磁電式信號(hào)發(fā)生器 B.霍爾式信號(hào)發(fā)生器 C.光電式信號(hào)發(fā)生器 D.斷電器觸點(diǎn)
A.轉(zhuǎn)矩 B.轉(zhuǎn)速 C.功率 D.效率
A.1/6 B.1/4 C.1/3 D.1/2