题目内容

步进电机开环进给系统的进给速度取决于()。

A. 指令脉冲频率f
B. 控制电流的大小
C. 指令脉冲的个数
D. 控制电压的大小

查看答案
更多问题

寄达地为三区的国内特快专递邮件一件,重()克,应收资费47元。

A. 800
B. 1000
C. 1500
D. 2000

Diesel engines driving alternators operating in parallel must maintain set frequency regardless of load changesThe governor characteristic used to accomplish this is known as ()

A. actuation
B. sensitivity
C. compensation
D. thrust shaft

某一小区5个载波(不开EDGE),SDCCH=5,若采用信令压缩,压缩因子为4,那么需要()个传输设备若采用信令复用(MULTIPLEX16),那么需要()个传输设备

A. 13,10
B. 12,10
C. 11,10
D. 11,11

A preferred-channel buoy will show a().

A. white light whose characteristic is Morse (A)
B. group-occulting white light
C. composite group-flashing (2 + 1) white light
D. composite group-flashing (2 + 1) red or green light

答案查题题库