1. [Multiple choice question] The following ( ) are organizational measures to ensure the safety of electrical work. （ a ）
a. Work permit system.
b. Power outage. c. Hang grounding wire.
2. [Multiple choice question] ( It is one of the technical measures to ensure the safety of electrical work. （ b ）
a. Work ticket system.
b. Electrical inspection. c. Work permit system.
3. [Multiple choice question] According to international and Chinese standards, the line can only be used as a protective grounding or protective neutral line. （ c ）
a. Black. b. Blue.
c. Yellow and green.
4. [Multiple choice] The power of the capacitor belongs to ( ) b ).
a. Active power.
b. Reactive power.
c. Apparent power.
5. [Multiple Choice] The current from the left hand to the feet causes ventricular fibrillation effect, and it is generally believed that the product of the energizing time and the current is greater than ( ) mA·s is life-threatening. （ c ）
a、16b、30
C, 506, [Multiple Choice] Insulation safety appliances are divided into ( ) safety appliances and auxiliary safety appliances. （ c ）
a. Direct. b. Indirect.
c. Basic. 7. [Multiple choice question] The multimeter is essentially a ( ) meter with a rectifier. （ a ）
a. Magnetoelectric.
b. Electromagnetic type.
c. Electric type.
8. [Multiple choice question] The total capacity of each lighting (including fan) branch is generally not greater than ( ) kw. （ b ）
a、2b、3
c, 49, [multiple choice] The unit of measuring resistance with a shake meter is ( )c ).
a. Ohms. b, thousand ohms.
c. Megaohms. 10. [Multiple choice] From the actual accidents, it can be seen that more than 70% of the accidents are related to ( ). （ c ）
a. Technical level.
b. People's emotions.
c. Human negligence.
11. [Multiple choice question] The principle of using AC contactor for under-voltage protection is that when the voltage is insufficient, the ( ) generated by the coil is insufficient, and the contact is broken. （ a ）
a. Magnetism. b. Eddy current.
c. Heat. 12. [Multiple Choice] The wire cutter with plastic handle used by the electrician has a voltage resistance of ( ) V or more. （ b ）
a、380b、500
c、1000
13. [Multiple choice] The direction of the electromotive force is ( )a).
a. From the negative pole to the positive pole.
b. From the positive electrode to the negative electrode.
c. Same as the voltage direction.
14. [Multiple choice question] The rated current of the melt of the lighting circuit fuse is ( ) times of the calculated current of the line. （ b ）
a、0.9b、1.1
c、1.515. [Multiple choice question] In the circuit, the switch should control ( ) b ).
a. Neutral line. b. Phase line.
c. Ground wire. 16. [Multiple Choice] The clamp ammeter is composed of a current transformer and a magnetoelectric meter with ( ). （ b ）
a. Measurement circuit.
b. Rectifier device.
c. Pointer. 17. [Multiple Choice] (The instrument is composed of a fixed coil, a rotating coil and a rotating shaft, a hairspring, a pointer, and a mechanical zeroing mechanism. （ c ）
a. Magnetoelectric.
b. Electromagnetic type.
c. Electric type.
18. [Multiple Choice] The power supply of mobile electrical equipment should be insulated with a high-strength copper core rubber sheath ( ) b ).
a. Wire. b. Cable.
c. Stranded wire. 19. [Multiple choice question] In order to prevent the stepping voltage from causing harm to people, it is required that the minimum distance between the lightning protection grounding device and the entrance and exit of the building and the sidewalk should not be less than ( ) meters. （ b ）
a、2.5b、3
c, 420, [Multiple Choice] The three elements to determine the sinusoidal quantity are ( ) b ).
a. Phase, initial phase, phase difference.
b. Maximum, frequency, initial phase angle.
c. Period, frequency, angular frequency.
21. [Multiple choice question] According to some data, if the heartbeat and breathing stop, about 80% of the rescue can be revived within ( ) min. （ a ）
a、1b、2
c, 322, [Multiple Choice] ( The instrument is composed of a fixed permanent magnet, a rotating coil and a rotating shaft, a hairspring, a pointer, and a mechanical zeroing mechanism. （ a ）
a. Magnetoelectric.
b. Electromagnetic type.
c. Induction.
23. [Multiple choice question] The autotransformer has 2 3 sets of taps for the second time, and its voltage can be % % of the primary voltage U1 and c ) respectively
a、10b、20
C, 6024, [Multiple Choice] The thermal relay has a certain ( ) automatic adjustment and compensation function. （ c ）
a. Time. b. Frequency.
c. Temperature. 25. [Multiple choice question] According to the provisions of the "Allowable Deviation of Power Quality Power Supply Voltage", the allowable deviation of three-phase power supply voltage of 10kV and below is ( ) b ) of the rated voltage
a、±5%b、±7%
c、±10%
26. [Multiple choice question] When several lines are erected on the same pole, it is necessary to ensure that the high-voltage line is in the low-voltage line ( ) c ).
a. Left. b. Right.
c. Above. 27. [Multiple Choice] In semiconductor circuits, fast fuses are mainly used for protection. （ a ）
a. Short circuit. b. Overvoltage.
c. Overheating. 28. [Multiple choice] Capacitors belong to ( ) equipment. （ c ）
a. Danger. b. Sports.
c. Stationary. 29. [Multiple choice question] Sometimes before measuring the current with a clamp meter, the jaws should be opened and closed several times, the purpose is ( ) b ).
a. Eliminate residual current.
b. Eliminate remanence.
c. Eliminate residual stress.
30. [Multiple choice] The power supply inlet of the spiral fuse should be connected to ( ) b ).
a. Upper end. b. Lower end.
c. Front-end. 31. [Multiple Choice] (The instrument is composed of a fixed coil, a rotating iron core and a rotating shaft, a hairspring, a pointer, and a mechanical zeroing mechanism. （ b ）
a. Magnetoelectric.
b. Electromagnetic type.
c. Induction.
32. [Multiple choice] The floor socket should have a firm and reliable ( ) b ).
a. Signs.
b. Protective cover.
c. Switch. 33. [Multiple choice question] When the low-voltage power supply line protection grounding and the lightning protection grounding network of the building need to be shared, the resistance of the grounding network is required ( ) a ).
a、≤1ωb、≤2.5ω
c、≤10ω
34. [Multiple choice question] Installation of leakage protection devices on electrical machinery and equipment at construction sites ( ). （ b ）
a. No. b. Should.
c. Not specified.
35. [Multiple choice question] For places with higher requirements for color differentiation, it is advisable to use ( ) b ).
a. Colored lanterns. b. Incandescent lamp.
c. Purple light.
36. [Multiple Choice] Electrical injury is the injury to the human body caused by the ( ) effect of electric current. （ c ）
a. Heat. b. Chemistry.
c. Thermal, chemical and mechanical.
37. [Multiple choice question] lightning rod is a commonly used lightning protection device, when installing, the lightning rod should be provided with an independent grounding device, if it is not in a high resistivity area, its grounding resistance should not exceed ( ) c ).
a、2b、4
C, 1038, [Multiple Choice] Low-voltage fuses, widely used in low-voltage power supply and distribution systems and control systems, mainly used for ( ) protection, sometimes can also be used for overload protection. （ b ）
a. Quick break. b. Short circuit.
c. Overcurrent. 39. [Multiple choice question] Special operations personnel must be at least ( ) years old. （ a ）
a、18b、19
c, 2040, [Multiple Choice] In the star connection of the three-dimensional symmetrical AC power supply, the line voltage is ahead of the corresponding phase voltage ( ) b ).
a、120b、30
C, 6041, [Multiple Choice] Low-voltage circuit breaker is also known as ( )c).
a. Gate knife. b. Main switch.
c. Automatic air switch.
42. [Multiple choice] iodine-tungsten lamp belongs to ( ) light source. （ c ）
a. Gas discharge.
b. Arc. c. Thermal radiation.
43. [Multiple Choice] When the voltage is 5V, the resistance value of the conductor is 5 ohms, then when the voltage at both ends of the resistance is 2V, the resistance value of the conductor is ( ) ohms. （ b ）
a、10b、5
C, 244, [Multiple Choice] When the staff works on electrical equipment of 10kV and below, the safety distance between the normal range of activities and the live equipment is ( ) meters. （ b ）
a、0.2b、0.35
c、0.545. [Multiple Choice] When the forward voltage is added at both ends of the PN junction, its forward resistance ( ) a ).
a. Small. b. Large.
c. No change. 46. [Multiple choice] Fluorescent lamps belong to ( ) light sources. （ a ）
a. Gas discharge.
b. Thermal radiation.
c. Biological discharge.
47. [Multiple Choice] In the use of multi-stage fuse protection, the rated current of the melt of the post-stage is larger than that of the pre-stage, so as to prevent the fuse from overstepping the fuse and ( ) c ).
a. Difficulty in obstacle inspection.
b. Reduce the scope of power outage.
c. Expand the scope of power outages.
48. [Multiple Choice] Pure capacitive components have electric energy in the circuit. （ a ）
a. Storage. b. Distribution.
c. Consumption. 49. [Multiple choice question] AC 10kV bus voltage refers to the AC three-phase three-wire system ( ) a).
a. Line voltage.
b. Phase voltage.
c. Line voltage.
50. [Multiple choice question] For low-voltage distribution network, when the distribution capacity is less than 100kw, the grounding resistance of the equipment protection grounding should not exceed ( ) a ).
a、10b、6
C, 451, [Multiple Choice] When checking the socket, the two holes of the electric pen in the socket are not lit, and the first judgment is ( ) b ).
a. Short circuit. b. The phase wire is disconnected.
c. The zero line is broken.
52. [Multiple choice] When working with low voltage electricity, (a).
a. Wear insulated gloves and be supervised.
b. Wear insulated gloves and do not be supervised.
c. Someone does not need to wear insulated gloves to supervise.
53. [Multiple Choice] The current of human ventricular fibrillation is about ( ) mA. （ c ）
a、16b、30
C, 5054, [Multiple Choice] Low-voltage electrical work refers to the installation, commissioning, operation and operation of electrical equipment below ( )v. （ c ）
a、250b、500
c、1000
55. [Multiple choice] The phase wire should be connected to the ( ) a ) of the screw lamphead
a. Center terminal.
b. Screw terminal.
c. Shell. 56. [True or False] The neutral wire after RCD can be grounded. （
57. [True or False] The voltage of the high-pressure mercury lamp is relatively high, so it is called a high-pressure mercury lamp. （
58. [True or False] The disconnector refers to the task of making and disconnecting the current and separating the circuit from the power supply. （
59. [True or False] When hanging the climbing board, the hook should be outward and upward. （
60. [True or False] The relationship between the period of sinusoidal alternating current and the angular frequency is reciprocal to each other. （
61. [True or False] Grounding or zeroing measures should be taken for such equipment and equipment. （
62. [True or False] Electricians should work in strict accordance with the operating procedures. （
63. [True or False] When measuring the current with a clamp meter, try to place the wire in the middle of the jaw core to reduce the measurement error. （
64. [True or False] Energy consumption brakingThis method converts the kinetic energy of the rotor into electrical energy and consumes it on the resistance of the rotor circuit. （
65. [True or False] The text symbol of the contactor is km. （
66. [True or False] The high voltage generated by lightning strikes can cause damage to electrical installations, buildings and other facilities, and damage to power facilities or power lines may lead to large-scale power outages. （
67. [True or False] Electric shock is divided into electric shock and electric injury. （
68. [True or False] The cross-section of the overhead insulated copper wire across the railway, highway, etc. shall not be less than 16mm. （
69. [True or False] The high voltage and dazzling white light generated by lightning strikes can cause damage to electrical installations, buildings and other facilities, and damage to power facilities or power lines may lead to large-scale power outages. （
70. [True or False] The text symbol of the contactor is fr. （
71. [True or False] The iron shell switch can be used to start the three-phase asynchronous motor below 28kw infrequently. （
72. [True or False] The combination switch can directly start the motor below 5kw. （
73. [True or False] DC arc burns are more serious than AC arc burns. （
74. [True or False] DC ammeter can be used for AC circuit measurement. （
75. [True or False] When starting with star-delta step-down, the starting current is 1 2 of the starting current when the triangle connection is directly used. （
76. [True or False] After the multimeter is used, the transfer switch can be placed in any position. （
77. [True or False] As long as the diode works in the reverse breakdown region, it will definitely be broken down. （
78. [True or False] After the capacitor is paralleled with an inductive load, the electrical angle between voltage and current decreases. （
79. [True or False] A symmetrical three-phase power supply is a power supply system composed of a sinusoidal power supply with the same amplitude and a difference of 120° in the initial phase. （
80. [True or False] The "departments responsible for the supervision and management of production safety" mentioned in the "Work Safety Law" refer to the departments of production safety supervision and management at all levels. （
81. [True or False] When an electrical fire occurs, if the power supply cannot be cut off, you can only extinguish the fire with electricity, and choose dry powder or carbon dioxide fire extinguishers, and try to use as few water-based fire extinguishers as possible. （
82. [True or False] The choice of RCD must consider the influence of the normal leakage current of the electrical equipment and circuit. （
83. [True or False] The position of the wire joint should be at the fixed place of the insulator as far as possible to facilitate the unified cable tie. （
84. [True or False] The grounding resistance tester is an instrument for measuring the insulation resistance of the line. （
85. [True or False] In a three-phase AC circuit, when the load is a star connection, the phase voltage is equal to the line voltage of the three-phase power supply. （
86. [True or False] In the operation of the equipment, the reason for the occurrence of ** is that the current heat is the indirect cause, and the spark or arc is the direct cause. （
87. [True or False] When lightning occurs, it should be forbidden to conduct high-altitude maintenance, testing and electrical inspection outside the house. （
88. [True or False] The common rated maximum working voltage of AC contactors reaches 6000V. （
89. [True or False] The magnitude of the voltage is measured with a voltmeter, and it is connected in series in the circuit when measuring. （
90. [True or False] In the electrical installation wiring diagram, all parts of the same electrical component must be drawn together. （
91. [True or False] After being disconnected from the power supply, the electrocuted person is conscious, and the electrocuted person should be allowed to walk back and forth to strengthen blood circulation. （
92. [True or False] The capacity of a capacitor is the capacitance. （
93. [True or False] The combination switch can directly start the motor below 5kw. （）
94. [True or False] Overload means that the current in the line is greater than the calculated current or allowable current carrying capacity of the line. （
95. [True or False] When the rotating electrical equipment is on fire, it is not advisable to use a dry powder fire extinguisher to extinguish the fire. （
96. [True or False] The power supply of mobile electrical equipment should be a high-strength copper-core rubber sheathed hard-insulated cable. （
97. [True or False] If the electrocuted person is delirious and has a heartbeat, but his breathing stops, he should immediately undergo mouth-to-mouth artificial respiration. （
98. [True or False] The use of lightning rods and lightning belts is the main measure to prevent lightning from damaging power equipment. （
99. [True or False] The frequency of sinusoidal alternating current in China is 50Hz. （
100. [True or False] The carbon dioxide fire extinguisher is only suitable for lines below 600V, if it is a 10kV or 35kV line, if you want to extinguish the fire with electricity, you can only choose a dry powder fire extinguisher. （