The main generators are connected to ______.

试卷相关题目

• 1Electric insulation is made of organic substances and so gradually ______with age.

  A.deteriorates

  B.increases

  C.are fouled

  D.becomes better

  开始考试点击查看答案
• 2The load sharing characteristics of two diesel generators operating in parallel are mostly dependent on their governor ______.

  A.load limit settings

  B.idle speed settings

  C.speed limit settings

  D.speed droop settings

  开始考试点击查看答案
• 3While paralleling two AC generators using synchronizing(同步的) lamps only, both lamps will go dark when the generators are ______.

  A.running at the same speed

  B.grounded

  C.of the same polarity(极性)

  D.in phase

  开始考试点击查看答案
• 4The frequency of an alternator at a given RPM is determined by the ______.

  A.number of turns of wire in the armature coil

  B.number of magnetic poles

  C.strength of the magnets used

  D.output voltage

  开始考试点击查看答案
• 5The current flowing first in one direction and then in another is called ____ current.

  A.a rush

  B.an alternating

  C.a direct

  D.an exciting

  开始考试点击查看答案
• 6The operation of _____ two alternators requires the voltages to be equal and also in phase.

  A.control

  B.series-mounting

  C.running

  D.paralleling

  开始考试点击查看答案
• 7______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

  开始考试点击查看答案
• 8A 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

  开始考试点击查看答案
• 9Time 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

  开始考试点击查看答案
• 10When voltage and current developed in an AC circuit reach their peak values at the same time, the power factor is ______.

  A.lagging

  B.leading

  C.maximum

  D.minimum

  开始考试点击查看答案