西交2012春季專業(yè)英語離線作業(yè)及答案

1、.成績西安交通大學現(xiàn)代遠程教育考試卷課 程:專業(yè)英語專業(yè)班號 考試日期 年 月 日姓 名 學號 期中 期末一 根據(jù)下面的英文解釋，寫出相應的英文詞匯。（共10分，每空1分）二. 根據(jù)電氣工程專業(yè)基本知識，判斷正誤。（共10分，每空1分）1. In alternating current an AC generator is used to make electrons flow continuously in one direction. _錯_2. In North American 50Hz is adopted as standard frequency in electric powe

2、r system. _錯_3. A computers microprocessor only understands high-level language. _錯_4. Instructions written in a high-level language must be translated into machine language in binary form before a computer can use them. _對_第 1 頁 共 6 頁5. In alternating current an AC generator is used to make electro

3、ns flow continuously in one direction. 錯_6. In China alternating current is usually generated at 60Hz. _錯_7. The north pole of the armature is attracted to the south pole of the main field. The south pole of the armature is attracted to the north pole of the main field. _對_8. When three capacitors c

4、onnected in series, . _錯_9. The commutator can change current direction in the conductor. _對_10. Most computers are equipped with a keyboard as the primary output device. _對_三. 基本詞匯的英漢互譯。（共15分，每題1.5分）1. _額定電流_ rated armature current 2. 理想電源 Ideal voltage source _ 3. _電路參數(shù)_ circuit parameters4. 周期電流

5、_ Periodic current _ 5. _負反饋_ negative feedback6. 直軸 _ Direct axis _ 7. 有功電流分量 _ Active component of current _ 8. _無功電流_ reactive current current9. 電網(wǎng) _ Power grid _ 10. _數(shù)字繼電器_ digital relays 四. 根據(jù)電氣工程基本知識，完成填空。（共30分，每空1分）1. Resistors are _ elements. A. passive B. active C. independent sources D. d

6、ependent sources2. An electric heater draws 10 A from a 120V line. The resistance of the heater is _. A. 1200 B. 120 C. 12 D. 1.23. The algebraic sum of all voltages around a loop is _. A. zero B. indefinite value C. sum of voltage rises D. sum of voltage drops4. ON-OFF information can be represente

7、d by _ signal. A. a digital B. an analog C. a discrete D. a control第 2 頁 共 6 頁5. In North American _ is adopted as standard frequency in electric power system. A. 25Hz B. 50Hz C. 60Hz D. 125Hz 6. _ can provide an asynchronous link between two ac electric power system with different nominal frequenci

8、es. A. The HVDC (high voltage DC) transmission B. The EHV (extra-high voltage) AC transmission C. The AC distribution D. Generators7. The generator voltages are usually stepped up to the transmission voltage level by _. A. series capacitor B. parallel reactors C. step-up transformers D. step-down tr

9、ansformers8. A D/A is a device that can convert a digital signal to the equivalent _. A. digital form B. numerical form C. binary form D. analog form9. The precision of ADC ( analog-to-digital conversion ) is determined by _. A. its speed B. its gain C. the accuracy of the reference voltage D. the n

10、umber of binary bits10. When an induction motor with 10 poles is supplied by 50Hz three-phase ac power source, the synchronous revolutions per minute is _. (Synchronous r/min = 120 f/p) A. 1000 B. 900 C. 700 D. 60011. A computer printer is _ device that produces computer-generated text or graphical

11、images on paper. A. an input B. an output C. a storage D. a data processing12. _ carries data out to speakers and headphones, or back from a microphone. A. A graphics card B. A modem C. A network card D. A sound card13. A computers microprocessor only understands _ in binary form. A. high-level lang

12、uages B. machine language C. human languages D. assembly language第 3 頁 共 6 頁14. Delphi belongs to _. A. low-level programming language B. high-level programming language C. a programming language connected with the computer hardware behavior D. an assembly language15. A floppy disk drive is _ device

13、 that reads data from and writes data to floppy disks. A. an input B. an output C. a storage D. a data processing16. In a coal-fired power plant, an electrostatic precipitator is used to remove _ from the combustion gases. A. solid particle B. C. CO D. water vapour17. In cogeneration（熱電聯(lián)產(chǎn)，熱電聯(lián)供） syst

14、ems, the overall energy efficiencies are raised by _. A. important the combustion process B. providing thermal energy to the customers C. raising the steam temperature D. reducing emissions18. The hydropower is well suited for switching according to _ command to meet changing power needs. A. a consu

15、mers B. a users C. a dispatchers D. an operators19. The total transfer function for and in cascade is不會_. A. B. C. D. 20. The systems characteristic equation can be used to determine _ of a linear time-invariant system. A. the stability B. magnitude of the steady-state error C. the controllability D

16、. the observability21. The Buck（降壓式變換器） is a _ converter. A. voltage step-up B. current step-down C. current step-up D. resistance22. A frequency response is a function of the variable _. A. B. C. D. 第 4 頁 共 6 頁23. The unit of logarithm of the magnitude of a transfer function is _. A. radians per se

17、cond B. volts C. decibel D. octaves24. The DC-DC converts _ input to _ output. A. direct current, alternating current B. direct current, direct current C. alternating current, alternating current D. alternating current, alternating current25. The primary winding is connected to _. A. the power sourc

18、e B. the load C. the measurement instrument D. the motor26. Copper losses are _ losses in the primary and secondary windings of the transformer core. A. inductive B. capacitive C. resistive D. reactive27. The relation results in _. A. null B. identity C. indefinite value D. zero28. The notebook comp

19、uters use _ as standard display equipment. A. CRT display B. LCDs C. LED D. TV screen29. An expansion slot is a long, narrow socket on the motherboard into which you can plug _. A. an expansion card B. a modem C. a network card D. a sound card30. The transformer is a straightforward application of F

20、aradays _ Law. A. Ohms B. Electromagnetic Induction C. Kirchhoffs Current D. Kirchhoffs Voltage五. 將下列短文翻譯為中文。（共20分，第1題12分，第2題8分）1. The coil to which the voltage is applied is known as the primary, while the one from which the induced voltage is obtained is known as the secondary. If the secondary ha

21、s more turns than the primary, the transformer is called a step-up transformer in which the AC voltage of the secondary winding is higher than that applied to the primary winding.第 5 頁 共 6 頁If the secondary has fewer turns than the primary, the transformer is called a step-down transformer in which

22、the AC voltage of the secondary winding is lower than that applied to the primary winding. In a well-built transformer the product of the secondary voltage multiplied by the secondary current is almost equal to the product of the primary voltage times the primary current.被施加電壓的繞組，稱為主繞組，從中感應出電壓的繞組稱為輔助繞組，如果輔助繞組線圈匝數(shù)大于主繞組的線圈匝數(shù)，則稱為升壓變壓器，升壓變壓器輔助繞組中的交流電壓大于主繞組中的交流電壓。如果輔助繞組中的線圈小于主繞組中的線圈匝數(shù)，則稱為降壓變壓器，降壓變壓器輔助繞組中的交流電壓小于主繞組中的交流電壓。一個質量優(yōu)良的變壓器的二次電壓同二次電流的乘積幾乎等于其一次電壓和一次電流的乘積。2. Noise is probably the only topic in electronics and telecommunication with which everyone must be famili