When voltage and current developed in an AC circuit reach their peak values at the same time, the power factor is ______.

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• 1Time delayed or delayed action-type fuses are designed to ______.

  A.prevent grounds in branch circuits

  B.prevent opens in motor circuits

  C.permit momentary overloads without melting

  D.guard lighting and electronic circuits

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• 2A ground in an electrical circuit outside the engine room ______.

  A.cannot be detected under normal conditions

  B.is of no consequence to engineering personnel

  C.is indicated at the branch circuit breaker panel

  D.is indicated by the ground detecting lamps on the main switchboard

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• 3______is a machine by which electrical energy is transformed into mechanical energy.

  A.An alternator

  B.An electric motor

  C.A diesel engine

  D.A main switchboard

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• 4The operation of _____ two alternators requires the voltages to be equal and also in phase.

  A.control

  B.series-mounting

  C.running

  D.paralleling

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• 5The main generators are connected to ______.

  A.distribution boards

  B.section boards

  C.emergency switch boards

  D.main switch boards

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• 6When 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

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• 7Before “stand by” is rung on the engine telegraph, it is usual to give the main diesel engine a brief trial ______ahead and astern.

  A.with power

  B.on power

  C.with air

  D.on air

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• 8Bridge orders must be ______and a record of any required changes in speed and direction should be kept.

  A.slowly carried away

  B.carried out with a period of delay

  C.promptly carried out

  D.paid by the captain

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• 9After the order ' ______' is given, the air system is shut down, the turning gear put in.

  A.Finished With Engine

  B.Stop The Engine

  C.Stand-by Engine

  D.Slow-down Engine

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• 10A tank has been sealed and unventilated(不通风的) for a long period of time. Which of the following conditions does this indicate、

  A.The tank is safe to enter.

  B.The tank is especially dangerous to enter.

  C.Carbon monoxide(一氧化碳) is present.

  D.Water vapor present when the tank was sealed has oxidized(使氧化).

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