單項(xiàng)選擇題Self-excited a-cgenerator with "error operated" voltage control systems draw the full excitation power for the machine terminalsThis dispenses with the current transformers, reactors and capacitors necessary for accurate compounding, but renders the excitation system vulnerable to variations in its output voltageWhich of the following is correct about the generator mentioned according to the sentences above （）.

A.It consumes no excitation power
B.It has current transformers
C.Components are needed for accurate compounding
D.Its excitation system is vulnerable to voltage variations


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2.單項(xiàng)選擇題If a steering motor becomes overloaded, the （）

A.overload condition of 5 % will trip the motor off the line immediately
B.overload condition will be indicated visually in the machinery space
C.motor running indicator will begin to flash "on" and "off" in response to the sustained overload condition
D.standby steering pump will start automatically and come on the line

3.單項(xiàng)選擇題When there is a fire in a large electric motor, normally the very FIRST step is to （）

A.secure the electric supply
B.ventilate area to remove smoke
C.start the fire pump and lead out hose
D.apply foam

4.單項(xiàng)選擇題When working on a high voltage circuit, you should always have another person present with you.This person should have a good working knowledge of （）

A.the circuit being worked on and the location of all switches and circuit breakers controlling it
B.first-aid techniques for treating electrical shock
C.cardiopulmonary resuscitation (CPR)
D.All of the above