二管轮第三章 船舶电气与船舶安全试卷.doc

试卷第 PAGE 1 页共 NUMPAGES 1 页 二管轮第三章 船舶电气与船舶安全试卷 姓名:_____________ 年级:____________ 学号:______________ 题型 选择题 填空题 解答题 判断题 计算题 附加题 总分 得分 评卷人 得分 1、Ammeter is to measure the _____. A.current B.voltage C.power D.frequency2、In a modern three-phase A.Csynchronous brushless generator, the excitation winding ison the rotorThat means _____. A.The generator needs not excitation B.The winding on the rotor is for inputting excitation current C.There are three phase windings on the rotor D.The generator has brushes3、The overcurrent relay _____ the motor contactor when the motor exceeds its rated current. A.connects B.trips C.fouls D.destructs4、The _____ is a measure of the phase difference between voltage and current and isexpected as the cosine of phase angle. A.power B.efficiency C.effective power D.power factor5、Current changing in direction and rising and falling in value is _____. A.A.C B.D.C C.generator D.fresh water generator6、The operation of paralleling two alternators requires the voltages to be _____ and alsoin phase. A.zero B.eliminated C.different D.equal7、The _____, cage rotor induction motor is the first choice marine motor in most modernships because of its electrical and mechanical simplicity. A.single phase B.two phase C.three phase D.four phase8、The star-delta starter is an effective method of _____ voltage starting of a motor. A.increased B.reduced C.unchanged D.None of the above9、With a _____ load the voltage and current are in phase. A.pure resistance B.capacitive C.inductive D.None of the above10、Sacrificial zinc anodes are used on the saltwater side of diesel engine heat exchangersto _____. A.reduce electrolytic action on heat exchanger metals B.keep heat transfer surfaces shiny and clean C.prevent rapid accumulation of marine growth D.provide a protective coating on heat exchanger surfac