单项选择题
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
A circuit that has one wire in contact with the hull of...
单项选择题A circuit that has one wire in contact with the hull of the ship is a（）
A.series circuit B.grounded circuit C.short circuit D.closed circuit
