单项选择题
A.When it is a DC machine B.When it is an AC machine C.Any machine that operates on over 100 volts D.Only when working on wet steel plates
The load between two steam-driven alternators operating...
单项选择题The load between two steam-driven alternators operating in parallel may be adjusted by varying （）
A.the speed of the alternators B.the field strength of the machines C.the power factor of the alternators D.steam supply to the prime movers
The purpose of the commutator and brushes on a DC gener...
单项选择题The purpose of the commutator and brushes on a DC generator is to（）
A.change AC to DCcurrent B.change DC to AC current C.neutralize a armature reaction D.carry current to the outside circuit
DC generators are classified according to the manner in...
单项选择题DC generators are classified according to the manner in which（）
A.they are used B.the field windings are connected to the load C.the armature circuit is connected to the load D.the field windings are connected to the armature circuit
