底托架具有支撑采煤机并使采煤机沿输送机()的功能。 ["平动","斜动","滚动","滑动"]
用兆欧表测量吸收比是测量()时绝缘电阻之比,当温度在10―30℃时吸收比为1.3―2.0时合格 ["15S和60S","15S和45S","20S和70S","20S和60S"]
铅蓄电池在汽车上主要用于()。 ["灯光照明","启动发动机","电能储存","电能释放"]
井下集电器与架空线的接触压力一般为()。 ["29~39N","39~49N","49~59N","59~69N"]
异步电动机实行能耗制动时,定子绕组中通入直流电流后,在电机内部将产生一个()的磁场。 ["静止","旋转","交变","脉动"]
公司所属单位建立健全基建安全保证体系和(),实行基建安全目标管理