Question bank source: Safety production mock test, one-stop public account applet
2024 [Electrician (Elementary)] Exam Summary and Electrician (Elementary) Exam Questions and Analysis, including Electrician (Elementary) Exam Summary Answers and Analysis and Electrician (Elementary) Exam Questions and Analysis Exercises. Combined with the latest syllabus of the National Electrician (Elementary) Examination and the summary of the real questions of the Electrician (Elementary) Exam, the safety production mock test is helpful for the pre-exam practice of the electrician (elementary) mock exam question bank.
1. [Multiple choice] () The incoming line should be connected to the upper end of the low-voltage circuit breaker. （ A ）
A. Power supply
B. Load
C. Resistance
D. Inductance
2. [Multiple Choice] When a resistor is connected to a power supply with an internal resistance of 0.1Ω and an electromotive force of 1.5V, the current flowing through the resistor is 1A, then the voltage on the resistor is equal to ()V. （ B ）
A、1
B、1.4
C、1.5
D、0.1
3. [Multiple choice question] A load with a power consumption of 1000 watts and a voltage of 180V should be measured according to the power meter limit of () scheme. （ D ）
A, 5 amps, 150 volts
B, 5 amps, 300 volts
C, 10 amps, 150 volts
D, 10 amps, 300 volts
4. [Multiple Choice] A single-phase bridge rectifier capacitor filter circuit, if the secondary voltage of the power transformer is known to be 10 volts, the circuit can output () volt voltage. （ D ）
A、9
B、4.5
C、10
D、12
5. [Multiple Choice] Three resistors R1, R2, and R3 are connected in series on the continuous flow power supply, and the relationship between the three resistors is known to be R1>R2>R3, then the voltage relationship assigned to them is (). （ B ）
A、U1=U2=U3
B、U1>U2>U3
C、U1<U2<U3
D、Ｕ2＞Ｕ1＞Ｕ3
6. [Multiple choice] The meaning of G in the transistor model 3DG201 is (). （ B ）
A. High voltage
B. High frequency and low power
C. Low power
D. Silicon material
7. [Multiple choice] The three-phase asynchronous motor has a short phase power supply in light load operation, and the motor is (). （ B ）
A. Stop immediately
B. Continue to rotate
C. Burn out immediately
D. It's all possible
8. [Multiple Choice] When the three-phase asynchronous motor is controlled in multiple places, if one of the stop buttons is not in good contact, the motor (). （ D ）
A. It will overcurrent
B. There will be a lack of phase
C. Can't be stopped
D. It cannot be started
9. [Multiple choice] The rotor of the three-phase asynchronous motor is composed of a rotor core, a fan, a rotating shaft, etc. （ B ）
A. Brushes
B. Rotor winding
C. End cap
D. Chassis
10. [Multiple Choice] When the three-phase motor auto-coupling step-down starter starts with 80% tap, the starting torque of the motor is ()% of the full-voltage starting torque. （ B ）
A、36
B、64
C、70
D、81
11. [Multiple Choice] The stator winding of the three-phase squirrel cage asynchronous motor is three symmetrical, and the electrical angle of each phase winding is different from each other (). （ C ）
A、60°
B、90°
C、120°
D、180°
12. [Multiple choice] The following () situation shows that the transistor is broken. （ C ）
A、e极PN结正向电阻很小
The reverse resistance of the PN junction at the B and e poles is very large
C、e极PN结正向电阻很大
The forward and reverse resistance of the PN junction at the D and e poles is very different
13. [Multiple choice question] Which of the following capacitors does not belong to organic dielectric capacitors (). （ D ）
A. Polyester dielectric capacitor
B. Polystyrene dielectric capacitors
C. Paint film dielectric capacitor
D. Multilayer capacitors
14. [Multiple choice question] The following data belong to the length specification of porcelain tubes. （ D ）
A、125mm
B、225mm
C、265mm
D、305mm
15. [Multiple Choice] Compared with aluminum wires, the following are not the advantages of copper wires. （ C ）
A. The resistivity is small
B. Good welding performance
C. Large resistivity
D. High mechanical strength
16. [Multiple choice question] The distance between the maximum sag of the temporary overhead line and the ground shall not be less than () at the construction site. （ B ）
A、3.5m
W、2.5m
C、5m
D、3m
17. [Multiple Choice] In order to reduce production costs, aluminum wire is commonly used instead of copper wire, and the resistivity of aluminum is known to be much greater than that of copper.
A, R copper = R aluminum
B, R copper> R aluminum
C, R copper
D. It has nothing to do with the working voltage
18. [Multiple choice question] The oil switch that is re-energized after the accident trip should be checked at least () times within 3 hours. （ D ）
A、2
B、3
C、5
D、8
19. [Multiple Choice] Among the electric shock methods of the human body, () is the most dangerous (B)
A. Single-phase electric shock
B. Two-phase electric shock
C. Step voltage electrocution
20. [Multiple choice question] The user shall conduct regular and regular inspections, () and maintenance of the construction lifting machinery and its safety protection devices, spreaders, rigging, etc., and make records. （ A ）
A. Maintenance
B. Repair
C. Oiling
D. Rust removal
21. [Multiple Choice] Full voltage start is only applicable to the case that the capacity of the motor is less than () kilowatts. （ D ）
A、75
B、17.5
C、10.5
D、7.5
22. [Multiple choice question] When making the main pole core of the DC motor, the material that should be selected preferentially is (). （ C ）
A. Ordinary thin steel sheet or thicker silicon steel sheet
B. Iron-nickel alloy
C. Silicon steel sheet with a thickness of 0.05~0.20mm
D. Iron and aluminum alloy
23. [Multiple Choice] The main power circuit is composed of a power switch, a contactor main contact, a thermal relay, a motor, etc. （ B ）
A. Button
B. Fuse
C. Time relay
D. Speed relay
24. [Multiple Choice] The power-on test sequence of the power main circuit should be (). （ A ）
A. Test the action of the contactor without connecting the motor first, and then connect the motor to test
B. Test the action of the motor first, and then test the action of the contactor
C. Test the operation of the thermal relay first, and then test the operation of the contactor
D. Test the action of the button first, and then connect the motor to test
25. [Multiple choice question] The wiring of the single-phase three-hole socket is specified as follows: the left hole is connected to (), the right hole is connected to the phase wire, and the middle hole is connected to the protection wire PE. （ A ）
A. Neutral line
B. Line of Fire
C. Ground wire
D. Switch
26. [Multiple choice question] The wiring method of the two-speed asynchronous motor should be (). （ C ）
A、△/Y
B、Y/△
C、YY/△
D、Y/△△
27. [Multiple choice question] The control circuit of the two-speed motor is to use () contactors to connect the stator winding into YY. （ B ）
A、1
B、2
C、3
D、4
28. [Multiple choice question] The ratio of the output power to the input power of the transformer is called (). （ B ）
A. Load rate
B. Efficiency
C. Load factor
D. Neither
29. [Multiple Choice] The function of transformer impedance conversion is often used in the occasion of (). （ D ）
A. Low-voltage power distribution
B. High-voltage power transmission
C. Power amplification
D. Impedance matching
30. [Multiple choice question] Without considering the complexity and economy, the following () motor speed regulation scheme is the best. （ C ）
A. Voltage and speed regulation
B. Electromagnetic speed regulation
C. Frequency conversion speed regulation
D. Pole change speed regulation
31. [Multiple Choice] The plastic sheath line is suitable for wet and corrosive special places, and the minimum distance from the ground shall not be less than () m when the indoor open application is applied. （ A ）
A、0.15
B、1.5
C、2
D、2.5
32. [Multiple Choice] As shown in the figure, it is known that the stable voltage of the regulator tube is 5.3V, and the voltage drop of the regulator tube when it is forward is 0.7V, the output voltage is () volts. （ B ）
A、5.3
B、1.4
C、10.6
D、6
33. [Multiple choice question] For the multi-place control of the three-phase squirrel cage asynchronous motor, multiple starting buttons must be connected in parallel and multiple stop buttons () in order to meet the requirements. （ A ）
A. Tandem
B. Parallel
C. Self-locking
D. Mixed linkage
34. [Multiple choice question] For a single operation, accident handling operation, opening the grounding switch and removing the only set of grounding wires, etc., () records should be made. （ C ）
A. Be sure to fill in the operation ticket
B. It should be recorded in the duty record
C. It should be recorded in the operation record
D. Loading work slip
35. [Multiple Choice] When the asynchronous motor is working in the braking state, () input the mechanical power. （ C ）
A. Frame
B. Power supply
C. On the shaft
D. End cap
36. [Multiple Choice] It is more difficult to disassemble the core of the transformer, because when the transformer is manufactured, it is impregnated with insulating paint together with the windings. （ C ）
A. The iron core is very heavy
B. The core is melted
C. The iron core is inserted very tightly
D. The cores are welded together
37. [Multiple Choice] When pulling out the steel tape measure, do not drag it back and forth on the ground to prevent the ruler from being carved (). （ D ）
A. Breakage
B. Bending
C. Deformation
D. Wear and tear
38. [Multiple Choice] The sinusoidal frequency range applicable to the analog multimeter is generally (A)
A. The highest grade
B. The lowest grade
C. Any file
39. [Multiple choice question] The grounding body is mostly made of (), and its cross-section should meet the requirements of thermal stability and mechanical strength. （ C ）
A. Any kind of metal material
B. Copper and aluminum material
C. Section steel
D. Insulated wire
40. [Multiple choice question] The lap length of the flat steel and the angle steel in the construction of the grounding grid should not be less than the width (). （ B ）
A, 1x
B, double
C, triple
D, quadruple
41. [Multiple choice question] Change the capacitive single, the safety production mock test is one-point, and the steering method of the asynchronous motor is (). （ D ）
A. The main and auxiliary windings are reversed
B. The phase line of the power supply is offset with the neutral line
C. Capacitor wiring is reversed
D. Any one of the main winding or auxiliary winding is reversed
42. [Multiple choice question] When laying wire pipes, when the length of the pipeline exceeds (), a distribution box or junction box should be installed in the middle of the pipeline. （ D ）
A、12m
B、20m
C、30m
D、45m
43. [Multiple Choice] Thermal relay is used for the protection of three-phase asynchronous motors. （ C ）
A. Short circuit
B. Loss of pressure
C. Overload
D. Grounding
44. [Multiple choice] When wiring the porcelain plywood, the core cross-section of the aluminum core wire should not be less than () mm2. （ B ）
A、1
B、1.5
C、4
D、6
45. [Multiple choice question] If the red pen of the multimeter touches one foot of the transistor, and the resistance measured by the black pen touching the other two pins is small, then the pin of the red pen is (). （ A ）
A. Base
B. Emitter
C. Collector
D. Unsure
46. [Multiple choice question] The rated voltage of the secondary side of the voltage transformer is specified as (). （ C ）
A、5伏
B, 50 volts
C, 100 volts
D. 150 volts
47. [Multiple choice] The charging time of the battery charger is calculated as (). （ A ）
A. Battery capacity divided by charging current
B. 3 times of the capacitor charging time constant
C. It has nothing to do with the size of the charging current
D. It has nothing to do with the added power supply voltage
48. [Multiple Choice] When the power supply voltage drops to 70% of the rated value, the incandescent lamp will (). （ D ）
A. Blue light
B. Completely extinguished
C. Flickering on and off
D. The lights are dimmed
49. [Multiple choice question] Cable fault acoustic measurement method is suitable for cable faults with grounding resistance greater than (). （ D ）
A、4Ω
B、10Ω
C、40Ω
D、150Ω
50. [Multiple Choice] In the short-circuit state, the current in the circuit (). （ A ）
A. Sharp increase
B. Decrease
C. No change
D, zero
51. [Multiple choice question] The largest coercivity and the largest magnetic energy product in magnetic materials are (). （ D ）
A. Silicon steel sheet
B. Iron-nickel alloy
C. Iron and aluminum alloy
D. Rare earth cobalt hard magnetic materials
52. [Multiple choice question] The characteristics of magnetoelectric instruments are (). （ A ）
A. Only DC can be measured
B. Only AC can be measured
C. Only pulsating DC can be measured
D. It can measure both DC and AC
53. [Multiple Choice] The voltage regulator circuit of the voltage regulator tube must have a () resistor with an appropriate resistance value. （ A ）
A. Current limiting and voltage regulation
B. Buck blood pressure
C. Current limiting
D. Voltage stabilization
54. [Multiple choice question] Professional ethics through (), plays a role in enhancing the cohesion of the enterprise. （ A ）
A. Coordinate the relationship between employees
B. Increase employee benefits
C. Create development space for employees
D. Regulate the relationship between enterprises and society
55. [Multiple Choice] The automatic Y-Δ step-down start-up control circuit is delayed through (). （ B ）
A. Thermal relay
B. Time relay
C. Contactor
D. Fuse
56. [Multiple choice question] The physical quantity that expresses the internal work ability of the power supply is called the () of the power supply. （ D ）
A. Terminal voltage
B. Potential
C. Current
D. Electromotive force
57. [Multiple choice question] The general steps of assembling an AC contactor are (). （ A ）
A. Moving iron core - static iron core - auxiliary contact - main contact - arc extinguishing cover
B. Moving iron core - static iron core - auxiliary contact - arc extinguishing cover - main contact
C. Moving iron core - static iron core - main contact - arc extinguishing cover - auxiliary contact
D. Static iron core - auxiliary contact - arc extinguishing cover - main contact - moving core
58. [Multiple choice question] The starting method of the wound asynchronous motor for lifting heavy objects on the crane is used (). （ B ）
A. The stator is connected to the three-phase voltage regulator method
B. Rotor string starting resistance method
C. Stator string starting resistance method
D. Rotor string frequency-sensitive rheostat method
59. [Multiple choice question] The corner rod and branch rod should be installed on one side of the () side when the unilateral horizontal "safety production mock test is a little clear". （ A ）
A. Pull the wire side
B. Tension side
C. Power supply side
D. Receiving side
60. [Multiple Choice] Overcurrent relay is mainly used in the occasion of (), as overload and short-circuit protection of motor or main circuit. （ B ）
A. Infrequent starting and heavy load starting
B. Frequent starting and heavy load starting
C. Frequent starting and light load starting
D. Light load starting and infrequent starting
61. [Multiple choice question] The model of the steel core aluminum stranded wire is (). （ B ）
A、LJ
B、LGJ
C、GJ
D、HLJ
62. [True or False] () When the three-phase load is connected in a triangle, and the current values of the three phases are equal, the three-phase load is a symmetrical load. （ × ）
63. [True or False] () Three-phase squirrel cage asynchronous motor can be started in Y/△ mode. （ × ）
64. [True or False] () The final metal sheath at the end of the three-core power cable. The safety production simulation test is easy to understand. Must be well grounded, plastic cable per phase copper shield and steel armor should tin solder ground wire. （ √ ）
65. [True or False] () The Electric Power Law of the People's Republic of China stipulates that the principle of who invests and who benefits from the investment of electric power enterprises shall be implemented. （ √ ）
66. [True or False] () The capacitor used in series has a small capacitor and a high voltage. （ √ ）
67. [True or False] () The main parameters of the diode are the maximum rectifier current and the maximum reverse working voltage. （ √ ）
68. [True or False] () The selection of AC contactors mainly includes the rated voltage and rated current of the main contact and the rated current of the suction coil. （ × ）
69. [True or False] () When working with low-voltage electricity, you must wear long-sleeved shirts. （ √ ）
70. [True or False] () The power and lighting distribution box is suitable for the power supply system with a rated voltage of less than 500V, and is used for power distribution and control of power and lighting equipment. （ √ ）
71. [True or False] () The shell of the "latest analysis" of the light-emitting diode is transparent and fully plasticized, and the color of the shell indicates its luminous color. （ √ ）
72. [True or False] () As long as a PN junction is damaged, the triode can be judged to be damaged. （ √ ）
73. [True or False] () In overhead lines, copper-aluminum alloy is widely used as a conductive material, and its model mark is HL. （ √ ）
74. [True or False] () The coil in the high-frequency circuit usually uses bakelite with low high-frequency loss as the skeleton. （ × ）
75. [True or False] () Voltage, current, and electromotive force that do not change in magnitude and direction with time are collectively referred to as direct current. （ √ ）
76. [True or False] () The current whose magnitude and direction do not change with time is called steady DC. （ √ ）
77. [True or False] () For circuits where the motor does not start frequently and the starting time is not long, the rated current of the melt is greater than 1.5 times of the rated current of the motor. （ × ）
78. [True or False] () For alternating current with periodic changes, the period is the time required for each cycle of alternating current. （ √ ）
79. [True or False] () In the era of market economy, diligence is needed, and thrift should not be promoted. （ × ）
80. [True or False] () Under the conditions of market economy, we should establish the concept of choosing a career by changing careers, learning more knowledge, and having more skills. （ × ）
81. [True or False] () Commonly used conduits include water gas pipes, electric conduits, PVC pipes, soft PVC pipes, self-extinguishing plastic conduits, metal hoses and porcelain pipes. （ √ ）
82. [True or False] () When the grounding body is installed horizontally, its burial depth should not be less than 0.6 meters. （ √ ）
83. [True or False] The low-load operation of the boiler will increase the loss of incomplete combustion and exhaust gas heat. （）（ √ ）
84. [True or False] () The tooth angle of ordinary threads is 60 degrees, and the tooth angle of inch threads is 55 degrees. （ √ ）
85. [True or False] () When the transistor is working in the amplified state, the emission junction is reversed, which is about 0.7V for silicon tubes and 0.3V for germanium tubes. （ √ ）
86. [True or False] () When replacing the fuse, try to choose a fuse with the same type of "Safety Production Mock Test One-to-One" specification, and install it reliably. （ √ ）
87. [True or False] () When measuring the current, the ammeter of the appropriate range should be selected according to the magnitude of the current, and the current should not be greater than the maximum range of the ammeter. （ √ ）
88. [True or False] () The grounding wire of the lampshade can be shared with the neutral wire of the lamp head. （ × ）
89. [True or False] () When cutting the insulation layer of the wire with an electrician knife, the knife can be slightly cocked and the fillet of the blade can be used against the core to prevent cutting the wire core. （ √ ）
90. [True or False] () The terminal voltage of the power supply decreases with the increase of load current. （ √ ）
91. [True or False] () The production of cable heads must be carried out continuously and completed at one time. （ √ ）
92. [True or False] () The cable is composed of two parts: a core and an insulating layer. （ × ）
93. [True or False] () The direct marking method of resistors refers to the method of marking its main parameters and technical performance in the product. （ × ）
94. [True or False] () When wiring pipelines, the dielectric strength of the wire insulation layer shall not be less than 500V, and the minimum cross-section of the aluminum core wire shall be 1mm2. （ × ）
95. [True or False] () Professional ethics is an important condition for the success of a person's career. （ √ ）
96. [True or False] () The automatic round-trip control line needs to realize the jog control of the motor for automatic conversion. （ × ）
97. [True or False] () The saw tooth of the saw blade is cut in the forward direction, so when installing the saw blade, the tip of the saw tooth should be pushed forward. （ √ ）
98. [Judgment Question] The standard of Chinese character symbols for electrical technology used in mainland China is the 1987 standard GB7159-87 "General Principles for the Formulation of Character Symbols in Electrical Technology", which replaces GB315-64. ()（ √ ）
99. [True or False] In a resistor series circuit, the larger the resistance, the greater the resistance divider()( √ )
100. [True or False] DC contactors and AC contactors work on the same principle. ()（ √ ）
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