单选题 Usually the panels are interlocked with ______ so that the devices can be made dead before the doors are opened.

单选题 Shore power must be ______ during dock repair.

单选题 Switchboard may be of the dead-front type in which all live parts are installed behind ______ and only the operation handles and instruments are on the front.

单选题 In a modern three-phase A.C. synchronous brushes generator, the excitation winding is on the rotor. That means ______.

单选题 The complete electrical plant on board ship is made up of power generation equipment, ______ and many power utilizing devices.

单选题 The voltage output of an A.C. generator is controlled by ______.

单选题 The frequency of the alternating current generated by a synchronous generator is governed by the speed and the ______.

单选题 The operation of paralleling two alternators requires the voltages to be ______ and also in phase.

单选题 If two A.C. generators are operated in parallel, the load is distributed evenly by ______.