單項選擇題

To parallel an incoming machine to a running machine therefore it is necessary to ensure firstly that （）.

A.two frequencies must be brought into phase
B.the incoming machine accepts a small amount of load
C.the running machine must be unload
D.both voltages are equal

你可能感興趣的試題

單項選擇題

The magnetic field is provided by electromagnets so arranged that adjacent poles have （）.

A.opposite polarity
B.the same polarity
C.negative polarity
D.positive polarity

單項選擇題

An a-cswitchboard is usually（） the corresponding d-cboard because of the higher voltage and lower currents and smaller bus-bars.

A.larger and heavier than
B.as much as
C.smaller and lighter than
D.more dangerous than

99色精品-9色在线-99色在线-99色视频 国产欧美日产一区二区三区_亚洲精品亚洲人成在线观看_四虎在线精品永久观看_免费一级a一片久久精

To parallel an incoming machine to a running machine therefore it is necessary to ensure firstly that （）.

你可能感興趣的試題

The magnetic field is provided by electromagnets so arranged that adjacent poles have （）.

An a-cswitchboard is usually（） the corresponding d-cboard because of the higher voltage and lower currents and smaller bus-bars.

99色精品-9色在线-99色在线-99色视频国产欧美日产一区二区三区_亚洲精品亚洲人成在线观看_四虎在线精品永久观看_免费一级a一片久久精