单项选择题
A.shunt field B.circuit breaker C.metal framework D.inter-pole
Brushless generators are designed to operate without th...
单项选择题Brushless generators are designed to operate without the use of（）.
A.brushes B.slip rings C.commutators D.all of the above
It （） for an emergency generator to require paralleling...
单项选择题It （） for an emergency generator to require paralleling.
A.is usual B.is not usual C.is necessary D.is not impossible
Usually the panels are interlocked with （） so that the ...
单项选择题Usually the panels are interlocked with （） so that the devices can be made dead before the doors are opened.
A.protective earth B.isolators C.ground switch D.circuit-breakers
