数控中级工试题

1、数控中级工试题Best answer: aclvaneed maintenance theory_60. Choose the right answer, and addthe letter of the response to the brackets in the questionIn the interstage coupling of multistage amplification circuit, the primary acceptanee (A) coupling of the low frequency voltage amplification circuit (A).(A

2、) the resistanee capacity (B) direct (C) transformer (D) inductaneeIf A straight line of current is directed from the north to the south, and A small magnetic needle that can be rotated by the top of it, the N pole of A small magnetic needle is tilted (A).(A) the west (B) east (C) south (D) north3.

3、According to the law of electromagnetic induction e = -/A t) and the induction electromotive force, is theA t this period of time (A)(A) the average (B) instantaneous value (C) the maximum value of the valid value (D)the coil electricIn an environment where the current rate of change in the coil is

4、constant, the self-inductance should be large, indicating that is large ? (A) flux (C) resistance (D) self-inductance Whenthe current is changed from 10A to 6A in 0. 5 seconds, the absolute value of the electromotive force on the coil is (C).(A) 4V (B) 0.4 V (C) 0.8 V (D) 8VThe polarity of the trans

5、former coil is generally determined by (D).(A) the right hand rule (B) the left hand rule (C) lenz law (D)The peak of the output collector voltage of the jt-1 transistor is (B) volt.(A) 100 (B) 200 (C) 500 (D) 1000The "brightness" on the oscilloscope panel is the potentiometer knob for reg

6、ulating (A).(A) the control grid negative voltage (B) the negative voltage (D) negative voltage (D)The，zX-axis selection should be placed in the (D) file when using the SBT -5 synchronous oscilloscope to inspect the standard light?(A) 1 (B) 10 (C) 100 (D) electron scanningWhen using the sr8 dual-tra

7、ck oscilloscope to look at the lower standard lights, the "being triggered ” switch in the“(C)" positionis advantageous.(A) high frequency (B) automatic (C) normal (D)General requirements for analog amplifiers (A) (A) it's A little bit bigger, the output resistance is smaller and theou

8、tput resistance is better(C) and the output resistors are good (D) and the output resistance is smallIn the sine wave vibrator, the phase difference between the feedback voltage and the original input voltage is (A)(A) 0 degrees (B) 90 degrees (C) 180 degrees (D) 270 degreesThe operational amplifier

9、, as shown in the image, belongs to (0(A) the multiplier (B) multiplier (C) differentiator (D)A multivibrator is a circuit that produces (C)?(A) sine wave (B) sawtooth wave (C) rectangular electronic pulse (D)The register is primarily composed of (D)(A) the vibrator (D) is triggered by the touch ini

10、tiator (D) and the gate circuitIn the dual anti-star controlled rectifier circuit with a balanced reactor, the load current is burdened by the (B) winding(A) A thyristor and A (B) two thyristor and two(C) three thyristor and three (D) four thyristor and four 17. In thyristor chopper, stabilizing the

11、 thyristor was touch trigger frequency, change of the thyristor con duction time and transform the moderation of the average de voltage postures pattern called (A)(A) fixed-frequency modulation (B), the wide frequency modulation (C), and the wide frequency modulation (D)The frequency of the output a

12、lternating current of the thyristor inverter is determined by (D).(A) A set of thyristor's lead time (B) of two sets of thyristor(C) a set of thyristor is triggered by the pulse frequency (D) of the electronic pulse frequency (D)The electric field effect tube MOSFETis suitable for working under

13、(D) conditions ?(A) de (B) low frequency (C) high frequency (D)The influence of electronic equipment against outside magnetic field is generally accepted (C) as a magnetic shield(A) paramagnetic (B) diamagnetic (C) ferromagnetic (D) insulationWhen the small transformer is made, the insulation betwee

14、n the core insulation and the winding is chosen according to the voltage of the voltage (B)(A) 1. 5 (B) 2 (C) 3 (D) 4After the rotor winding of the ac motor is repaired, the position ofthe band (B) is bound to the position of the band(A) 1 2 ? 3 (C) 5 (D) 5 6The probable cause of obstruction is (A)

15、when the three-phase motor is too high or smoke ?(A) the three-phase induction motor (B) rotor is out of balance(C) stator, winding phase friction (D) winding moisture permeatesThe short-circuitexperiment of transformer is held under theof (A)inductioncondition(A) low voltage side short circuit (B)

16、short circuit (C) low pressure side open (D)The de generator is rotated by the drag of the original motive, and the armature cutter is produced (A).(A) sinusoidal alternating current (B) non-sinusoidal alternating current (C) direct current (D)The commutator of the de motor must be with the armature

17、 winding (A).The (A) series (B) is in parallel direction(C) direct (D) in the otherThe mechanicalproperties of thede motor are hard, and whenthe motor loadis increased,its speed (B).(A) landing A lot (B) landing is very rare (C) stable (D) slightly upIt is known thatthe electromagnetic power of a ce

18、rtain motoris 9 power units, the speed is n = 900 , and its electromagnetic distance is (D) ox (A) 10 (B) 30 (C) 100 (D) 300 / PIWhen the three-phase induction motor is in reverse braking, it is acceptable to accept the symmetrical resistance method, which can limit the braking torque and limit (A).

19、(A) the brake current (B) starts the working current (C) braking voltage(D) begins the working voltageThe de generator has (A) type in the field pattern of excitation (A) 2 (B) 3 (C) 4 (D) 5The stator iron core of the transformer and the core of the rotor,(B) material to make, insulation, and stack.

20、(A) an electrician USESA pure iron (B) high permeability silicon or iron nickel alloy plateC) non-magnetic alloy (D) soft magnetiteThe speed n and electronic pulse frequency (A) of the reflected step motor ?(A) f is proportional (B) f is inversely proportional (C) f2 is proportional (D) f2 is invers

21、ely proportionalThe working principle of de torque motor is different from (A) motor(A) ordinary de servo (B) asynchronous (C) synchronization (D) stepThe shift of the differential motor is driven by (C)(A) the machine (C) working machine (C) three-phase squirrel-cage induction motor (D) is the magn

22、etic pole of the differential clutchThe three-phase asynchronous commutator motor is adjusted to the speed, and the moving brush mechanism will use the Angle between the same phase brush and the Angle of (A).(A) -180 degrees (B) 180 degrees (C) 0 degrees (D) 90 degreesacceptsteelminimumThe VVVF freq

23、uency converter, which is used in frequency conversion, has (C) function(A) modulation (B) frequency modulation (C) modulation and frequency modulation (D)Three-phase shunt commutator motor speed adjustment applies to (C) load(A) the constant torque (B) gradually increases the distance(C) constant p

24、ower (D) decreases the distanceThe inverter circuit of the inverter motor ?(A) there is A large capacitor (B) string with A large inductance (C) and A large capacitor (D) and A large inductanceWhen the constant torque speed adjustment is achieved, the frequency modulation is also (C)?(A) there is no

25、 need to adjust the voltage (B) without the mediation of the current (C) necessary to mediate the voltage(D) it is necessary to mediate the current(B) when the direct current motor is adjusted for the chopper.(A) there is A speed regulating (B) stepless speed adjustment(C) permanent fixed speedIn th

26、e rev system,In order to make the open loop and the closed-loop system in the air speed, the voltage in the closed loop is higher than the given voltage response at the open loop (B)(A) 2 + K (B) 1 + K (C) 1 over (2 + K) (D) 1 / (1 + K)Voltage and negative feedback automatic adjustment system, the s

27、peed regulating range D is usually (A)(A) D < 10 (B) D > 10 (C) 10 < 20 (D) 20 < 30Double closed loop speed control system with the ring of pregnancy and the speed ring ? The two rings are between the two rings (A).(A) the current ring is the inner ring, and the rate ring is the outer ri

28、ng(B) the ring is the outer ring, and the speed ring is the inner ring(C) the current ring is the inner ring, and the speed ring is the inner ring(D) the current loop is the outer ring, and the speed ring isalso the outer ringThe primary skill parameters of the sensor synchronizer are dynamic range

29、? The degree of precision, the resolution, the dynamic range is (C)?(A) 0. 2 ? 40m (B) 0. 2 ? 20m (C) 0. 3 40m (D) 0. 3 20m(C) it is an outline controlled number control machine (A) numerically controlled machine tool (B) nc drilling machine(C) processing center (D) nc perforation machineThe VVVF el

30、evator acceptance (C) will be used for speed adjustment(A) change the logarithmic logarithm (B) to change the rate of change(C) change the power supply voltage and frequency (D) to change the voltageThe tendency of the computer to grow is huge, miniaturized, networked, and intelligentized ?(A) large

31、 (B) mass (C) has more external equipment(E) the function is stronger, the operation rate is faster and the reserves are largerThe focus of the microcomputer is (C)(A) the memory (B) bus (C) CPU (D) I/O interface(B) the application of microcomputer in in dustrial production(A) intelligent instrument

32、ation (B) automatic selling of machine tools(C)(C) the motor began to work and stopped temperanceThe PLCmanufacturers in China have used (A) as the language of the chief user programming languageThe (A) ladder diagram (B) order table (C) mind function graph (D) C languageThe output voltage of the si

33、ngle-phase bridge inverter (voltage) is (B)(A) the sine wave (B) rectangle wave (C) sawtooth wave (D)The way to shorten the basic time is (A)(A) to improve the level of the process (B) to shorten the converse time(C) cut down time (D) to cut back on timeThe way to shorten the time for converse is (A

34、) (A) A large amount of promotion of skill reform and skill modification (B) reduction of course time (C) cut down time (D) to cut back on timeIt is appropriate to use (D) connection for large, demanding eventsThe (A) flat key (B) semicircle (C) key (D)The advantage of belt drive is (C)(A) speed is

35、more efficient than accurate (B) * * * compact (C) transmission smoothing (D)A good tooth for a straight toothed cone gear is (C) (A) ml 二 m2 (B) al 二 a2 (C) ml = m2 = a2 (D) ml = m2 = m2 = m al = a2 = AThe ratio of the gear transmission system to the end of the gear transmission system is equal to

36、the ratio of the gear transmission system(B)(A) all active gear-drive system Numbers are multiplied by the product of all the pinion(B) all the products of the driving system of the driven gear are the product of all the active wheel teeth(B) the two active wheels and the wheel(C) the middle inert n

37、umber 559.7000 hints (B) bearing(A) push the ball (B) roller (C) rollerThe easy to measure in the hydraulic drive is (A)(A) pressure and f 1 ow (B) leakage noise (C) shock vibration (D) temperatureTwo. Question (61 ? 80. Fill in the brackets ? Good square root, incorrect ?(x) 61. The magnetic circui

38、t, as well as the circuit, is open(X) 62. With the transistor tracer investigate the input characteristics of the commonemitter amplifier circuit, the X axis utility switch should be placed in the base voltage, Y switch in the base current utility or base source voltage(square root) 63. Whenusing an

39、 oscilloscope, you should be able to plug the standard light into the Y input button(x) 64. The synchronous oscilloscope generally accepts the continuous electronic scanning pattern(x) 65. The most effective way to overcome zero drift is to accept ac negative feedback circuits (square root) 66.The v

40、oltage stabilizer of silicon stabilizer is only in small load, and the output voltage is not as low as random adjustment(x) 67. The thought rule of the door can be summarized as 0 out of 0,1 out of 1The concentric winding of the transformer often assembles thelow pressure, and the high pressure is a

41、ssembled outsideThe brush of the de motor is usually depressed by the grey powder(square root) 70. Self-integral Angle motor is a kind of induction electromechanical element(x) 71. The non-commutation direct current motor is an inductor that accepts the ring and the brush without the commutator(x) 7

42、2. Current to negativefeedback is involved in regulating utility(square root) 73. The size of a magnetic grid to output the banner light is in dependent of the speed of the magnetic ruler and the magnetic ruler(square root) 74. SCR - D drags the form of a de elevator to the de elevator(x) 75. When s

43、omeone touches the safety board during the communication elevator, the lift still closes(x) 76. In order to ensure the safe operation of the PLCcommunication, the safe contact points are accepted into the input interface of PLC(x) 77. When the PLC communication escalator * state, pressing down the d

44、e key lift is rapidly reaching the required layer(x) 78. PLC programmable control is held in parallel mode(x) 79. There is at least one crank in the simplest of four barsThe first parameter of the chain is the pitch1, the fixed power transformer refers to when a side with fixed voltage, the temperat

45、ure rise shall not exceed the allowed temperature of the environment, the secondary side is allowed by the maximum power output ? (x)2, the transformer is used is the iron heart will gradually oxidize and rust, ? So the vacuum is going to be less responsive? (x)The speed of the three-phase induction

46、 motor depends on the frequency of the power supply and the logarithmic frequency, and is independent of the rate of change ? (x)The lower the speed of the rotor of the three-phase induction motor, the higher the speed of the motor, the more the rotor electromotive force frequency ? （fx）Five, the ap

47、plication of short circuit tester to check whether or not one phase short circuit, three-phase induction motor winding for multi-channel and winding or parallel branch, required each branch first open it. （ fx ）The output voltage of the transformer is bound to decrease regardless of the load of the

48、subnature of the transformer, as long as the load current continues to increase?（ x）Any contact with an arc cover shall develop an electric motor in the rear of an arc cover?（ x）In order to see the benefit of the light load, the light load test will allow the non-extinguishing arc to start the motor

49、?Eight, series magnetic blow out arc pattern, the direction of magneticblow is independent of current direction ? The direction of the magnetic blow is independent of the current direction.（x ）The short circuit ring of the ac contact iron will make the movement of the heart not less than release?（ x

50、）When the parameters in the circuit change, the voltage between the two points will also change,（ x）The scale of the electromotive force is proportional to the rate of the coiT s electric current, which has nothing to do with the power of the coils ?（ fx ）For the perceptual circuit, the total curren

51、t in the circuit decreasesif the voltage of the power supply is stable and the power frequencyis increased ?（ fx ）The electronic tube voltmeter can be measured in de, ac, sinusoidal and non-sinusoidal standard?（ x）The electronic oscilloscope can only be detected by the waveform of the banner light,

52、and it is less than the size of the light that is used for measurement ?（ x）The power factor of a pure resistance circuit must be equal to 1, andif the power factor of a circuit is 1, the circuit must be a circuitwith only resistance?（ x）16, from no load to full load, with the increase of the load c

53、urrent, copper loss and the temperature of the transformer is increased, the primary and secondary windings in the synthesis of magnetic flux of iron heart also will increase?（ x）When the transformer is empty, the active component of the current issmall, and the reactive component is large, and the power factor is low. （fx）A three-phase induction motor with a fixed load torque, if the voltageis lower than the norm, the current will be lower than the fixed current ?（ x）If the film in the oil