1. The general relay can be replaced with coils of different properties, so as to make various relays. (1.0 points) Correct Answer: True.
2. The protection characteristics of the thermal relay should be as close as possible to the overload characteristics of the motor when protecting the motor. (1.0 points) Correct Answer: True.
3. The text symbol of the button is SB. (1.0 points) Correct Answer: True.
4. The shell must be reliably grounded when the iron shell switch is installed. (1.0 points) Correct Answer: True.
5. The low-voltage circuit breaker is an important control and protection electrical appliance, and the circuit breaker is equipped with an arc extinguishing device, so it can safely close and open the load. (1.0 points) Correct Answer: True.
6. The text symbol of the time relay is km. (1.0 points) Correct Answer: False.
7. The text symbol of the contactor is fr. (1.0 points) Correct Answer: False.
8. The characteristics of the fuse are that the higher the voltage value through the melt, the shorter the fusing time. (1.0 points) Correct Answer: False.
9. The intermediate relay is actually a voltage relay with adjustable action and release values. (1.0 points) Correct Answer: False.
10. When there is leakage or someone is electrocuted in the protected circuit, the zero-sequence current transformer will generate an induced current, which will be amplified to make the tripper act, so as to cut off the circuit.
1.0 points) Correct Answer: True.
11. When the multimeter pointer swings when the capacitor is measured, it stops moving, indicating that the capacitor is short-circuited. (1.0 points) Correct Answer: True.
12. There should be good ventilation in the capacitor room. (1.0 points) Correct Answer: True.
34. For the wound asynchronous motor, the contact between the brush and the collector ring and the wear, pressure, spark and other conditions of the brush should be checked frequently. (1.0 points) Correct Answer: True.
13. When checking the capacitor, just check whether the voltage meets the requirements. (1.0 points) Correct Answer: False.
14. In order to avoid accidents caused by electrostatic sparks, all kinds of flammable liquids and gases should be isolated separately when processing, transportation, storage and other flammable liquids and gases. (1.0 points) Correct Answer: False.
15. In thunderstorm weather, even indoors, do not repair electrical wiring, switches, sockets, etc. at home. If you must repair it, pull the main power switch at home open. (1.0 points) Correct Answer: False.
16. The lightning protection device should be laid along the outer wall of the building, and grounded in the shortest way, and can be concealed if there are special requirements.
3 p. 43.
1.0 points) Correct Answer: True.
17. TT system is a system in which the neutral point of the distribution network is directly grounded, and the shell of electrical equipment also adopts grounding measures. (1.0 points) Correct Answer: True.
18. The protection zero connection is suitable for the distribution system where the neutral point is directly grounded. (1.0 points) Correct Answer: True.
19. For electrical equipment powered by single-phase 220V power supply, three-pole leakage protection device should be selected. (1.0 points) Correct Answer: False.
20. The residual current action protection device is mainly used for low-voltage systems below 1000V. (1.0 points) Correct Answer: True.
21. When hanging the climbing board, the hook should be outward and upward. (1.0 points) Correct Answer: True.
22. Electrical inspection is one of the technical measures to ensure the safety of electrical work. (1.0 points) Correct Answer: True.
23. When using the foot buckle for pole climbing operation, each step of the upper and lower rod must make the foot buckle fully inserted and reliably buckle the pole in order to move the body, otherwise it will cause an accident. (1.0 points) Correct answer: Current at Hz 40Hz is most dangerous. (1.0 points) Correct Answer: False.
25. The risk of two-phase electric shock is smaller than that of single-phase electric shock. (1.0 points) Correct Answer: False.
26. Electric shock is divided into electric shock and electric injury. (1.0 points) Correct Answer: True.
27. Insulation aging is only a chemical change. (1.0 points) Correct Answer: False.
28. According to the nature of electricity, power lines can be divided into power lines and distribution lines. (1.0 points) Correct Answer: False.
29. The line investment must be considered when selecting the wire, but the cross-sectional area of the wire should not be too small. (1.0 points) Correct Answer: True.
30. Overload means that the current in the line is greater than the calculated current or allowable current carrying capacity of the line. (1.0 points) Correct Answer: True.
31. Insulating material refers to a material that is absolutely non-conductive. (1.0 points) Correct Answer: False.
32. When laying power lines, it is strictly forbidden to loosen the wires by suddenly cutting the wires. (1.0 points) Correct Answer: True.
33. The fuse can play an overload protection role in all circuits. (1.0 points) Correct Answer: False.
34. For the wound asynchronous motor, the contact between the brush and the collector ring and the wear, pressure, spark and other conditions of the brush should be checked frequently. (1.0 points) Correct Answer: True.
35. In order to improve the starting and running performance of the motor, the rotor core of the cage asynchronous motor generally adopts a straight groove structure. (1.0 points) Correct Answer: False.
36. For the inspection of the lubrication of the motor bearing, the motor shaft can be rotated by energizing to see if it rotates flexibly and whether there is any abnormal sound. (1.0 points) Correct Answer: False.
37. The motor that uses changing the number of pole pairs to regulate the speed is generally a wound rotor motor. (1.0 points) Correct Answer: False.
38. After the motor is overhauled, after passing the inspection, the motor can be tested for no-load test and short circuit test. (1.0 points) Correct Answer: True.
39. The electrical control system diagram includes an electrical schematic diagram and an electrical installation diagram. (1.0 points) Correct Answer: True.
40. In the electrical installation wiring diagram, all parts of the same electrical component must be drawn together. (1.0 points) Correct Answer: True.
41. Grounding or zeroing measures should be taken for such equipment and equipment. (1.0 points) Correct Answer: False.
42. The length of the handle of the No. 1 electrician's knife is longer than that of the No. 2 electrician's knife. (1.0 points) Correct Answer: True.
43. Electrician's pliers, electrician's knives, and screwdrivers are commonly used electrician's basic tools. (1.0 points) Correct Answer: True.
44. The table lamp of the screw lamp head should use a three-hole socket. (1.0 points) Correct Answer: True.
45. Each circuit of the street lamp should be protected, and each lamp should be equipped with a separate fuse. (1.0 points) Correct Answer: True.
46. The low-voltage electroscope can detect the voltage below 500V. (1.0 points) Correct Answer: False.
47. The electroscope must be confirmed to be good before use. (1.0 points) Correct Answer: True.
48. After the leakage switch trips, it is allowed to check the line by means of shunt power failure and power transmission. (1.0 points) Correct Answer: True.
49. Incandescent lamps are thermal radiation light sources. (1.0 points) Correct Answer: True.
50. In order to be safe and reliable, all switches should control the phase line and the neutral line at the same time. (1.0 points) Correct Answer: False.
51. 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. (1.0 points) Correct Answer: False.
52. In the most dangerous places, the three-phase four-wire system and single-phase three-wire system should be used for power supply. (1.0 points) Correct Answer: False.
53. Defects in electrical equipment, unreasonable design, improper installation, etc. are all important causes of fire. (1.0 points) Correct Answer: True.
54. The maintenance and maintenance of daily electrical equipment shall be the responsibility of the equipment management personnel. (1.0 points) Correct Answer: False.
55. Electricians should operate in strict accordance with the operating procedures. (1.0 points) Correct Answer: True.
56. Personnel who have obtained a senior electrician certificate can engage in electrical work. (1.0 points) Correct Answer: False.
57. Apparent power is reactive power plus active power. (1.0 points) Correct Answer: False.
58. As long as the diode works in the reverse breakdown area, it will definitely be broken down. (1.0 points) Correct Answer: False.
59. Kirchhoff's first law is the nodal current law, which is used to prove the relationship between currents on a circuit. (1.0 points) Correct Answer: True.
60. In any case, the transistor has the function of current amplification. (1.0 points) Correct Answer: False.
61. The symbol "A" indicates AC power supply. (1.0 points) Correct Answer: False.
62. Magnetic field lines are a kind of closed curve. (1.0 points) Correct Answer: True.
63. The time required for each alternating current for one week is called period t. (1.0 points) Correct Answer: True.
64. Before using the shake meter, there is no need to check whether the shake watch is in good condition, and the insulation measurement can be carried out directly on the tested equipment. (1.0 points) Correct Answer: False.
65. The positive direction of the electromotive force is specified to be from the low potential to the high potential, so the positive pole of the voltmeter should be connected to the negative pole of the power supply, and the negative pole of the voltmeter should be connected to the positive pole of the power supply. (1.0 points) Correct Answer: False.
66. When the voltmeter is measured, the range should be greater than or equal to the voltage of the line to be measured. (1.0 points) Correct Answer: True.
67. When the multimeter measures the resistance, the pointer is the most accurate in the middle of the dial. (1.0 points) Correct Answer: True.
68. The magnitude of the current is measured with an ammeter, and it is connected in parallel in the circuit when measuring. (1.0 points) Correct Answer: False.
69. The clamp ammeter can be made to measure both AC current and DC current. (1.0 points) Correct Answer: True.
70. After the multimeter is used, the transfer switch can be placed in any position. (1.0 points) Correct Answer: False.