单项选择题
A.slightly less than the line frequency B.the same as the line frequency C.slightly greater than the line frequency D.All of the above
Which of the following should be the FIRST step in remo...
单项选择题Which of the following should be the FIRST step in removing a generator from parallel operation?（）
A.Trip the generator off the switchboard B.Turn off all electrical equipment C.Remove the load from the "off going" generator D.Increase the cycles of the generator staying on the line
Electrical power is expressed in （）A.ohmsB.voltsC.ampsD...
单项选择题Electrical power is expressed in （）
A.ohms B.volts C.amps D.watts
Which of the following materials is a good insulator?（）...
单项选择题Which of the following materials is a good insulator?（）
A.steel B.aluminum C.glass D.copper
