2022 low voltage electrician test questions and simulation test

Source of question bank ： Safety production simulation test, a little public official account.

2022 The title of low voltage electrician certificate in is low voltage electrician examination 100 The whole question is simulated ！2022 Low voltage electrician test questions and simulation test are based on the new low voltage electrician test outline . Low voltage electrician exam simulation questions pass the one-point learning progress analysis of safety production simulation exam .

1、【 Single topic selection 】 Transportation of liquefied gas , When the tanker of oil, etc. is running , Metal chain or conductive rubber shall be used at the bottom of the tank car to make it contact with the earth , Its purpose is to ( ).（  B  ）

A、 Neutralize the static charge generated during the running of the tank car

B、 The static charge generated during the running of the leaking tank car

C、 Equipotential between the tank car and the earth

2、【 Single topic selection 】 The unit of power of a capacitor is ( ).（  A  ）

A、 Lack

B、 watts

C、 volt-ampere

3、【 Single topic selection 】 It's flammable 、 Explosive and dangerous places , The electrical circuit shall adopt ( ) Or armored cable laying .（  C  ）

A、 Wear metal coiled tubing and then lay sand along the cable trench

B、 Through the water and gas pipe

C、 Threading steel pipe

4、【 Single topic selection 】 In distribution lines , When the fuse is used for overload protection , The rated current of the melt shall not be greater than the allowable current carrying capacity of the conductor ( ) times .（  C  ）

A、1.25

B、1.1

C、0.8

5、【 Single topic selection 】 Be marked with “100 o 4 watts ” and “100 o 36 watts ” The two resistors are connected in series , The maximum voltage allowed is ( )V.（  B  ）

A、20

B、40

C、60

6、【 Single topic selection 】 Special operation certificate ( ) Annual review 1 Time .（  C  ）

A、5

B、4

C、3

7、【 Single topic selection 】(GB/T3805-2008)《 Extra low voltage (ELV) limit 》 Specified in the , In a normal environment , During normal operation, the limit of effective value of power frequency voltage is ( )V.（  A  ）

A、33

B、70

C、55

8、【 Single topic selection 】 In three-phase AC circuit ,A Phase use ( ) Color mark .（  B  ）

A、 Red

B、 yellow

C、 green

9、【 Single topic selection 】 Replace the melt or tube , Must be in ( ) In the case of .（  B  ）

A、 Electrification

B、 Not electrified

C、 With load

10、【 Single topic selection 】 In the circuit , The switch shall control ( ).（  B  ）

A、 Zero line

B、 Phase line

C、 Ground wire

11、【 Single topic selection 】 Three phase asynchronous motor shall be designed according to its requirements ( ) The difference can be divided into open 、 Protective 、 There are three types of closed type .（  B  ）

A、 Mode of power supply

B、 Enclosure protection mode

C、 Structural type

12、【 Single topic selection 】( ) The instrument consists of a fixed coil , Rotatable coil and rotating shaft 、 Gossamer 、 The pointer 、 Mechanical zero adjustment mechanism, etc .（  C  ）

A、 Magnetoelectric

B、 Electromagnetic

C、 Electric

13、【 Single topic selection 】 Breaking capacity of AC contactor , It means that the switch can reliably switch off the current ( ) The ability of .（  B  ）

A、 Separate the contacts

B、 Extinguish the arc

C、 Cut off the operation

14、【 Single topic selection 】 In order to prevent step voltage from harming people , It is required that the lightning protection grounding device shall be away from the entrance and exit of the building 、 The minimum distance between sidewalks shall not be less than ( ) rice .（  B  ）

A、2.5

B、3

C、4

15、【 Single topic selection 】 When the current relay is used, its suction coil is directly or through the current transformer ( ) In the controlled circuit .（  B  ）

A、 parallel connection

B、 Series connection

C、 Series or parallel

16、【 Single topic selection 】 The grounding resistance measuring instrument is mainly composed of a hand generator 、( )、 Potentiometer , And galvanometer .（  A  ）

A、 Current transformer

B、 Voltage transformer

C、 transformer

17、【 Single topic selection 】( ) The instrument consists of a fixed permanent magnet , Rotatable coil and rotating shaft 、 Gossamer 、 The pointer 、 Mechanical zero adjustment mechanism, etc .（  A  ）

A、 Magnetoelectric

B、 Electromagnetic

C、 Inductive

18、【 Single topic selection 】 The two basic principles that should be followed in the correct selection of electrical appliances are safety principle and ( ) principle .（  B  ）

A、 performance

B、 economic

C、 function

19、【 Single topic selection 】 Unipolar semiconductor devices are ( ).（  C  ）

A、 diode

B、 Bipolar diode

C、 Field effect tube

20、【 Single topic selection 】 The function of adding steel core to aluminum strand is ( ).（  C  ）

A、 Improve conductivity

B、 Increase the conductor area

C、 Improve mechanical strength

21、【 Single topic selection 】 When the human body contacts two-phase conductors in live equipment or lines at the same time , An electric current flows from one phase through the human body into another , This phenomenon of electric shock is called ( ) Get an electric shock .（  B  ）

A、 single-phase

B、 two-phase

C、 Inductive electricity

22、【 Single topic selection 】 according to 《 Allowable deviation of power quality supply voltage 》 Regulations ,10kV The allowable deviation of three-phase power supply voltage of and below is... Of the rated voltage ( ).（  B  ）

A、±5%

B、±7%

C、±10%

23、【 Single topic selection 】 Making capacity of AC contactor , It means that when the switch is closed and the current is connected, it will not cause ( ) The ability of .（  A  ）

A、 Contact fusion welding

B、 The arc appears

C、 Voltage drop

24、【 Single topic selection 】 The floor socket shall have firm and reliable ( ).（  B  ）

A、 Sign Board

B、 Protective cover plate

C、 switch

25、【 Single topic selection 】 Electrical and mechanical equipment on construction site ( ) Install leakage protection device .（  B  ）

A、 Should not

B、 Should be

C、 No rules

26、【 Single topic selection 】

The following figures ,（） Is the electrical graphic of the button .

（  A  ）

A、

B、

C、

27、【 Single topic selection 】 In case of grounding fault of electrical equipment , The grounding current flows to the earth through the grounding body , If a person walks around the ground short circuit point , The electric shock caused by the potential difference between the two feet is called ( ) Get an electric shock .（  B  ）

A、 single-phase

B、 Step voltage

C、 Inductive electricity

28、【 Single topic selection 】

The graphical symbol of the diode is .

（  A  ）

A、

B、

C、

29、【 Single topic selection 】 In the course of production , Static electricity on human body , For the equipment , It is harmful to products , To eliminate or reduce static electricity , Spray wetting agent can be used. , The purpose of this is ( ).（  C  ）

A、 Let the static charge leak through the air

B、 Make the static charge radiate and leak around

C、 Make static electricity leak along the insulator surface

30、【 Single topic selection 】 When the wall switch is installed, the height from the ground is ( )m.（  A  ）

A、1.3

B、1.5

C、2

31、【 Single topic selection 】 The grounding wire shall be multi strand soft bare copper wire , Its cross-sectional area shall not be less than （）m㎡.（  C  ）

A、6

B、10

C、25

32、【 Single topic selection 】 Transformer and high voltage switchgear , The main measures to prevent damage caused by lightning intrusion are ( ).（  A  ）

A、 Install lightning arrester

B、 Installation of lightning conductor

C、 Install lightning protection network

33、【 Single topic selection 】 In three-phase symmetrical AC power star connection , The line voltage is ahead of the corresponding phase voltage ( )°.（  B  ）

A、120

B、30

C、60

34、【 Single topic selection 】 The main cause of electro-optic ophthalmia is ( ).（  C  ）

A、 Infrared

B、 Visible light

C、 Ultraviolet (uv)

35、【 Single topic selection 】 Electrical fire is caused by the existence of dangerous temperature , The dangerous temperature is mainly caused by ( ).（  C  ）

A、 Light equipment load

B、 Voltage fluctuation

C、 The current is too high

36、【 Single topic selection 】 The asynchronous motor starts at the moment , The current induced in the rotor winding is very large , The starting current flowing through the stator is also large , About... Of the rated current ( ) times .（  B  ）

A、2

B、4-7

C、9-10

37、【 Single topic selection 】 When the combined switch is used for reversible control of motor ,( ) Allow reverse connection .（  C  ）

A、 It is not necessary to stop after the motor stops completely

B、 It can be started after the motor stops

C、 Only after the motor stops completely

38、【 Single topic selection 】 In power control system , The most widely used is ( ) Type AC contactor .（  B  ）

A、 Pneumatic

B、 electromagnetism

C、 Hydraulically

39、【 Single topic selection 】 In general lighting circuit , The basis of no electricity is ( ).（  B  ）

A、 Measure with a megger

B、 Check electricity with a pencil

C、 Measure with an ammeter

40、【 Single topic selection 】 Application of soldering transistor and other weak current components ( )W It's better to use electric soldering iron .（  A  ）

A、25

B、75

C、100

41、【 Single topic selection 】 If the victim's heart stops , Breathing , The person who gets an electric shock should be treated immediately ( ) First aid .（  B  ）

A、 Supine chest compression

B、 Extrathoracic cardiac compression

C、 Prone back pressing method

42、【 Single topic selection 】 On each single-phase circuit in the lighting system , The number of lamps and sockets should not exceed ( ) individual .（  B  ）

A、20

B、25

C、30

43、【 Single topic selection 】 The iron case switch is used to control the start and stop of the motor , The rated current is required to be greater than or equal to ( ) Times the rated current of the motor .（  B  ）

A、 One

B、 two

C、 3、 ... and

44、【 Single topic selection 】 The inside of the inductive fluorescent lamp ballast is ( ).（  B  ）

A、 electronic circuit

B、 coil

C、 Oscillating circuit

45、【 Single topic selection 】 The specification of the screwdriver is based on the length of the rod body outside the handle and ( ) Express .（  C  ）

A、 radius

B、 The thickness of the

C、 The diameter of

46、【 Single topic selection 】 When installing electrical circuits , The connection process between wires or between wires and electrical bolts that is most likely to cause fire is ( ).（  A  ）

A、 Copper wire and aluminum wire are twisted

B、 Aluminum wire is twisted with aluminum wire

C、 Copper aluminum transition joint crimping

47、【 Single topic selection 】 In general places , To ensure safe use , Should be selected ( ) Electric tool .（  B  ）

A、Ⅰ class

B、Ⅱ class

C、Ⅲ class

48、【 Single topic selection 】 When replacing and overhauling electrical equipment , The best safety measure is ( ).（  A  ）

A、 Cut off the power supply

B、 Standing on a stool

C、 Wear rubber gloves to operate

49、【 Single topic selection 】 The phase line shall be connected to the of the screw lamp cap ( ).（  A  ）

A、 Center terminal

B、 Threaded terminals

C、 Shell

50、【 Single topic selection 】 In order to check, you can cut off power for a short time , Before touching the capacitor, you must ( ).（  A  ）

A、 Fully discharge

B、 Long time power failure

C、 After cooling

51、【 Judgment questions 】 The starting torque of rotor series frequency sensitive rheostat is large , Suitable for heavy load starting .（  ×  ）

52、【 Judgment questions 】Ⅱ This kind of hand-held electric tool is better than Ⅰ Such tools are safe and reliable .（  √  ）

53、【 Judgment questions 】 Current will form in the rotor conductor of three-phase asynchronous motor , The current direction can be determined by the right-hand rule .（  √  ）

54、【 Judgment questions 】 Electrical control system diagram includes electrical schematic diagram and electrical installation diagram .（  √  ）

55、【 Judgment questions 】 Lightning can discharge to human body through other charged bodies or directly , Cause great damage to human body until death .（  √  ）

56、【 Judgment questions 】 The bimetallic sheet of thermal relay is rolled by a metal material with different coefficient of thermal expansion .（  ×  ）

57、【 Judgment questions 】 The line investment must be considered when selecting the conductor , But the cross-sectional area of the conductor should not be too small .（  √  ）

58、【 Judgment questions 】 For wound asynchronous motors, the contact between the brush and the collector ring and the wear of the brush shall be checked frequently , pressure , Sparks, etc .（  √  ）

59、【 Judgment questions 】 When measuring current with clamp meter , Try to place the conductor in the middle of the jaw core , To reduce measurement errors .（  √  ）

60、【 Judgment questions 】 When the capacitor explodes , Check immediately .（  ×  ）

61、【 Judgment questions 】 When measuring current, the ammeter shall be connected in series with the circuit under test .（  √  ）

62、【 Judgment questions 】 When the single strand conductor with small cross-sectional area is flat connected, the splicing method can be used .（  √  ）

63、【 Judgment questions 】 Insulating materials are materials that are absolutely non-conductive .（  ×  ）

64、【 Judgment questions 】 Under the same conditions , Alternating current is more harmful to human body than direct current .（  √  ）

65、【 Judgment questions 】 Electric shock accident is an accident caused by electric energy acting on human body in the form of current .（  √  ）

66、【 Judgment questions 】 Electricity inspection is one of the technical measures to ensure the safety of electrical operation .（  √  ）

67、【 Judgment questions 】 In everyday life , In and flammable 、 Pay attention when contacting with explosives ： Some media are easy to generate static electricity and even cause fire and explosion . For example, metal barrels can not be used to hold oil at the gas station .（  ×  ）

68、【 Judgment questions 】 office 、 School 、 Enterprises 、 There is no need to install leakage protection devices for socket circuits in residential buildings and other buildings .（  ×  ）

69、【 Judgment questions 】 The power transformation and distribution equipment shall be equipped with perfect screen protection device .（  √  ）

70、【 Judgment questions 】 The high voltage and dazzling white light generated by lightning can cause damage to electrical installations, buildings and other facilities , Damage to power facilities or power lines may lead to large-scale blackouts .（  ×  ）

71、【 Judgment questions 】 Thunderstorm weather , Don't repair electrical wiring at home even indoors 、 switch 、 Socket, etc . If you have to repair it, turn off the main power switch at home .（  ×  ）

72、【 Judgment questions 】 Rated current of AC contactor , Is the current value determined under rated working conditions .（  √  ）

73、【 Judgment questions 】 The symmetrical three-phase power supply is composed of the same amplitude 、 The initial phases differ in sequence 120° Sinusoidal power supply , Composition of the power supply system .（  ×  ）

74、【 Judgment questions 】 In the magnetic circuit , When the magnetoresistance is constant , The magnetomotive force is proportional to the inverse magnetic flux .（  ×  ）

75、【 Judgment questions 】 Special operation certificate 1 It shall be reviewed once a year by the examination and Certification Department .（  ×  ）

76、【 Judgment questions 】 The way to discharge a capacitor is to connect its two ends with wires .（  ×  ）

77、【 Judgment questions 】 Check whether the ground wire is well grounded by the method of phase wire touching the ground wire .（  ×  ）

78、【 Judgment questions 】 In three-phase AC circuit , When the load is star connection , The phase voltage is equal to the line voltage of the three-phase power supply .（  ×  ）

79、【 Judgment questions 】 The lightning rod can be welded with galvanized steel pipe , Its length should be within 1m above , The diameter of steel pipe shall not be less than 20mm, The thickness of pipe wall shall not be less than 2.75mm.（  ×  ）

80、【 Judgment questions 】 When the fluorescent lamp is on , The ballast has the function of reducing voltage and limiting current .（  √  ）

81、【 Judgment questions 】 Enterprises 、 An institution uses personnel without corresponding qualifications to engage in special operations , Major casualties occurred , Sentenced to fixed-term resettlement or criminal detention of not more than three years .（  √  ）

82、【 Judgment questions 】 Making and breaking capacity of AC contactor , It is related to the structure of contactor and arc extinguishing mode .（  √  ）

83、【 Judgment questions 】 In addition to the independent lightning rod , On the premise that the grounding resistance meets the requirements , The lightning protection grounding device can be shared with other grounding devices .（  √  ）

84、【 Judgment questions 】 Characteristics of fuse , The higher the voltage through the melt , The shorter the fusing time .（  ×  ）

85、【 Judgment questions 】 After lightning, the overhead line will produce high-voltage shock wave , This kind of lightning is called direct lightning .（  ×  ）

86、【 Judgment questions 】 For places prone to static electricity , The ambient humidity should be kept at 70% above .（  √  ）

87、【 Judgment questions 】 Enterprises 、 Employees of public institutions engage in special operations without special operation certificate , Operation against regulations .（  √  ）

88、【 Judgment questions 】 The low-voltage distribution panel connects the relevant low-voltage components according to a certain wiring scheme 、 Assemble the secondary equipment , Each main circuit scheme corresponds to one or more auxiliary schemes , Thus, the engineering design is simplified .（  √  ）

89、【 Judgment questions 】 After the power failure , The motor stops , When the grid calls again , The operation mode in which the motor can start by itself is called voltage loss protection .（）（  ×  ）

90、【 Judgment questions 】 The grounding resistance meter is mainly composed of a hand generator 、 Current transformer 、 Potentiometer and galvanometer .（  √  ）

91、【 Judgment questions 】 The daily maintenance of electrical equipment shall be the responsibility of the equipment management personnel .（  ×  ）

92、【 Judgment questions 】 When using electrical equipment , Because the conductor section is too small , When the current is large, it will also cause fire due to excessive heating .（  √  ）

93、【 Judgment questions 】 Overload means that the current in the line is greater than the calculated current or allowable current carrying capacity of the line .（  √  ）

94、【 Judgment questions 】 The installation height of sockets in children's activity places such as kindergartens and primary schools should not be less than 1.8m.（  √  ）

95、【 Judgment questions 】 This method of changing rotor resistance speed regulation is only applicable to wound asynchronous motor .（  √  ）

96、【 Judgment questions 】 Yellow and green conductors can only be used for protective wires .（  √  ）

97、【 Judgment questions 】 The character symbol of time relay is KM.（  ×  ）

98、【 Judgment questions 】 AC clamp ammeter can measure AC and DC current .（  ×  ）

99、【 Judgment questions 】 The total resistance after several resistors are connected in parallel is equal to the reciprocal sum of each parallel resistance .（  ×  ）

100、【 Judgment questions 】 The wiring of hand-held electric tools can be lengthened at will .（  ×  ）

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