单项选择题
An electrical device which employs a stationary armature and a rotating electromagnetic field is used aboard ship as a （）.
A.magnetic amplifier B.ship’s service alternator C.three-wire DC generator D.saturable core reactor
单项选择题 As a general rule, the first troubleshooting action to be taken in checking faulty electric control devices is to （）.
单项选择题 A circuit breaker differs from a fuse in that a circuit breaker （）.
单项选择题 Voltage generated by most AC generators is fed from the machine to the bus by means of（）.
