当前测试题类型单选1. For supplying more electricity, what kind of voltage is used?A14V AC powerB115V AC powerC14V DC powerD28V DC power回答错误你的答案正确答案B2. In a metal airplane, what is used as a return wire?Aaircraft frameBcopper wireCaluminum wireDiron wire回答错误你的答案正确答案A3. Which is better conductor?AcopperBaluminumCsteelD(NO)回答错误你的答案正确答案A4. Why the wiring is coated [涂上、蒙上]with tin, silver, or nickel?ATo help prevent oxidationBTo make the wire harCTo decrease the resistance of wireD(NO)回答错误你的答案正确答案A5. If a transformer变压器has turns ratio of 12, and inputs of 240 V and 5 amps, the output voltage is ( )A60VB120VC240VD480V回答错误你的答案正确答案D6. If a transformer has turns ratio of 12, and inputs of 240 V and 5 amps, the output current is ( )A2.5AB5AC10AD20A回答错误你的答案正确答案A7. In star connection three-phase AC system, phase voltage is 115V, the line voltage is ( )A55VB115VC200VD230V回答错误你的答案正确答案C8. In star connection连接three-phase AC system, phase current is 100A, the line current is ( )A50AB100AC173AD200A回答错误你的答案正确答案B9. In delta三角形connection three-phase AC system, phase current is 100A, the line current is ( ) A50AB100AC173AD200A回答错误你的答案正确答案C10. A transformer rectifier unit (TRU) is used to convert ( )ADC power to ACBAC power to DCCDC power to DCDAC power to AC回答错误你的答案正确答案B11. A frequency-wild generator can be used to operate circuits containing ( )Aresistive componentsBinductive componentsCcapacitive componentsD(NO)回答错误你的答案正确答案A12. If an over voltage occurs发生, ( ) reset复位may be attempted尝试，试图.AoneBtwoCthreeDfour回答错误你的答案正确答案A13. On modern aircraft, the Constant Speed Drive Unit (CSDU) and generator are normally combined as one unit, which is known as ( )ATRUBIDGCVSCFDINV回答错误你的答案正确答案B14. The Differential Protection circuit is used to monitor ( )Aline-to-earth faultsBunder-voltage faultsCover-voltage faultsDunder-frequency faults回答错误你的答案正确答案A15. What kind of electrical power is used in relay coil?( )ADC voltageBAC voltageCDC or AC voltageD(NO)回答错误你的答案正确答案A16. In a LA battery, the active material on a charged positive plate is( )ALead Dioxide (PbO2)BLead (Pb)CLead sulphate (PbSO4)D(NO)回答错误你的答案正确答案A17. In a LA battery, the active material on a charged negative plate is ( ) ALead Dioxide (PbO2)BLead (Pb)CLead sulphate (PbSO4)D(NO)回答错误你的答案正确答案B18. For a nickel-cadmium battery,the active material on the positive plate is ( ) Anickel hydroxideBcadmium hydroxideCNickelDcadmium回答错误你的答案正确答案A19. For a nickel-cadmium battery,the active material on the negative plate is ( ) Anickel hydroxideBcadmium hydroxideCNickelDcadmium回答错误你的答案正确答案D20. In a DC generator, which opponent is used to convert 转换AC to a DC? ( )Acommutator换向器BarmatureCfieldDfan回答错误你的答案正确答案A当前测试题类型判断1. According to the service of load, category of bus bar is divided into Vital ,essential,non-essential.回答错误你的答案正确答案对2. The master switch needs to be ON for any other electrical system to receive power, or for the battery to be recharged when the engine is running. It should be turned OFF after stopping the engine, to avoid the battery discharging via services that are connected to it.回答错误你的答案正确答案对3. Relays and solenoids (contactor) are quite similar, with only a mechanical difference.回答错误你的答案正确答案错4. "Solid-State-Relay" (referred to as 'SSR' for short) means switching without any mechanical means. It does not have any moving components.回答错误你的答案正确答案对5. The fuse is placed in series with the load (component) it protects. However, the circuit breaker is placed in parallel with the load.回答错误你的答案正确答案错6. The advantage of a circuit breaker over a fuse is that a circuit breaker can be reset once the overload situation has been remedied.回答错误你的答案正确答案错7. In the trip-free system depressing the reset button will not remake the circuit, nor will it reset the circuit breaker, until the overload condition has been cleared.回答错误你的答案正确答案对8. The cell voltage has dropped only a very small amount when the cell is 50% discharged.回答错误你的答案正确答案错9. Residual magnetism may be lost, or its polarization reversed, due to excess heat, shock or reversal of field current flow.回答错误你的答案正确答案对10. An ammeter is connected in series with each generator to show the output current (load). A voltmeter is connected in parallel with circuit loads to show circuit voltage.回答错误你的答案正确答案对11. A negative phase sequence would result in the three-phase motor running in the wrong direction.回答错误你的答案正确答案对12. The Constant Speed Drive Unit (CSDU) is positioned between the aircraft engine and the brushless AC generator.回答错误你的答案正确答案对13. The CSDU is designed to keep the generator running at a constant speed, and gives a constant output frequency of 400 Hz.回答错误你的答案正确答案对14. The oil pressure and temperature of the CSDU are very important, so we need to monitor them on the flight deck.回答错误你的答案正确答案对15. Once the CSDU has been disconnected, it can be reset in flight.回答错误你的答案正确答案错16. In order to prevent inadvertent CSDU disconnect, the CSDU disconnect switches are normally guarded and locked with thin copper wire.回答错误你的答案正确答案错17. In Variable Speed Constant Frequency (VSCF) system, no solid-state circuitry is fitted.回答错误你的答案正确答案错18. The APU can be used to supply compressed air and electrical power.回答错误你的答案正确答案对19. During the approach to landing, the RAT may become inefficient, so the aircraft batteries take over and supply the necessary loads during the final approach.回答错误你的答案正确答案对20. The generators in frequency-wild system can run in parallel.回答错误你的答案正确答案错21. The frequency-wild system is often used on turbo-propeller aircraft.回答错误你的答案正确答案对22. If an over voltage occurs, a sensing circuit automatically de-excites the generator and removes it from the busbar.回答错误你的答案正确答案对23. Before paralleling can take place between two generators, voltages must be exactly same.回答错误你的答案正确答案错24. Before paralleling can take place between two generators, frequencies must be within tolerance.回答错误你的答案正确答案对25. One advantage of Constant Frequency Parallel AC System is that its protection circuitry is very cheap.回答错误你的答案正确答案错26. One advantage of Split Busbar AC System is that it can provides continuity of electrical supply.回答错误你的答案正确答案错27. Reactive load sharing is achieved by a load-sharing loop, which automatically adjusts the excitation of the paralleled generator fields simultaneously via their individual voltage regulators.回答错误你的答案正确答案对28. Real load sharing is achieved by adjusting the speed of the CSDUs.回答错误你的答案正确答案对29. Time delays are not needed in the generator protection system.回答错误你的答案正确答案错30. The TRUs are normally run in parallel on large aircraft.回答错误你的答案正确答案对。