单项选择题
A.paralleling B.series-mounting C.running D.control
With a purely （） load the voltage and current are in ph...
单项选择题With a purely （） load the voltage and current are in phase, giving a power factor of one.
A.inductive B.resistance C.combined D.capacitate
The separate supplies are connected in either star or d...
单项选择题The separate supplies are connected in either star or delta formationThe star formation is most commonly used and requires（） slip-rings on the alternator.
A.two B.three C.four D.five
After a ship enters service it is（） for the main bus-ba...
单项选择题After a ship enters service it is（） for the main bus-bar to be made dead.
A.usually B.commonly C.exceptional D.unavoidably
