First, multiple-choice questions (1 point for each question, a total of 30 points)
1. See the following signs in the working environment, indicating () A. Pay attention to safety B. Beware of electric shock C. Beware of infection
2. International regulations, the voltage () volts or less does not have to consider the danger of preventing electric shock. A. 36 volts B. 65 volts C. 25 volts
3. The red line in the three-wire cable represents (). A. Zero line B. FireWire C. Ground wire
4. When the power is off and overhauled, which of the following signs should be hung on the operating handle of the switch or knife gate that can be sent to the work site after closing? ()
A. " Working here" B. "Stop, high pressure danger" C. "No closure, some people work"
5. Most of the electric shock accidents are caused by personal injury or death. A. The human body receives electric current and is shocked. Burn C. Electric shock
6, if the electric shock is serious, breathing stops or the heart stops beating, you should try to perform () and chest compression.
A. Massage B. Acupoint C, artificial respiration
7. What is the following fire extinguishing method that cannot be used when the appliance is on fire? ()
A. Use carbon tetrachloride or 1211 fire extinguisher to extinguish the fire. Use sand to extinguish fire C. Extinguish with water
8, the electrostatic voltage can be up to (), can be discharged in the field, generate static sparks, causing fire. A. 50 volts B. Tens of thousands volts C220 volts
9. The use of the leakage protector is to prevent (). A. Electric shock accident B. Voltage fluctuation C. Charge overload
10. What kind of adverse reactions will the operator have under the action of high-frequency electromagnetic fields for a long time? () A. Suction difficulty B. Neurological disorders Fatigue
11. Which of the following fire extinguishers are suitable for extinguishing electrical fires? () A. Carbon dioxide fire extinguisher B. Dry powder fire extinguisher C. Foam fire extinguisher
12. What kind of workplace is not suitable for metal ladders? () A. There is a workplace where the motor will be touched. Pit or closed place C. Working at height
13. When the high-voltage power line is broken, the wire is broken within the meter and the personnel are prohibited from entering. () A. 10B. 20C. 30
14. Which of the following precautions is correct when using a hand-held power tool? () A. Use universal socket B. Use leakage protector C. Wet body or clothes
15. The dangerous voltage for an electric shock accident generally begins with () volts. A. 24B. 26C. 65
16. When using electrical equipment, due to improper maintenance, when () enters, it may cause a short circuit accident.
A. Conductive dust or fiber B. Strong light radiation C. heat
17. When the fixed wire sockets in the factory are damaged, it will cause (). A. Inconvenience caused by work B. Unsightly C. Electric shock
18. Which of the following is the voltage of the civil lighting circuit? () A. DC voltage 220 volts B. AC voltage 280 volts C. AC voltage 220 volts
L9. When repairing the high voltage motor. Which of the following behaviors is wrong?()
A. First, implement the power-off safety measures, and then carry out maintenance work on the circuit of the high-voltage motor and its accessories.
B. At the end of the overhaul work, when the high-voltage motor and its starting device need to be energized, all the workers should be evacuated from the site and then sent for trial operation.
C. Perform maintenance work on the ground wire of the running high voltage motor.
20. Which of the following statements about the use of leakage protectors is correct? ()
A. The leakage protector can be used to protect personal safety and can also be used to supervise the insulation of the low voltage system or equipment.
B. The line after the leakage protector installation point cannot be insulated from the ground.
C. In daily use, the leakage protector should not be pressed in the power-on state to check whether it is sensitive or reliable.
21. What kind of safety technical measures are involved in the installation of leakage protectors? () A. Basic security measures B. Auxiliary security measures C. Absolute security measures
22. Under the action of electromagnetic field, the human body will cause different degrees of damage to the human body. () A. Current B. Voltage C. Electromagnetic radiation
23. If the workplace is wet, to avoid electric shock, the person using the hand-held power tool should ().
A. Standing on the iron plate, operate B. Standing on the insulating rubber plate, operate C. Wear anti-static shoes
24, lightning discharge has the characteristics of (). A. The current is large and the voltage is high. The current is small and the voltage is high. Large current, low voltage
25. The height of the light and dark sockets in the workshop from the ground is generally not less than () how many meters? A. 0.3 m B. 0.2 m C. 0.1 m
26. What fire extinguishers can't be used when fighting electrical equipment fires?()
A. Carbon tetrachloride fire extinguisher B. Carbon dioxide fire extinguisher C. Foam fire extinguisher
27. Any electrical equipment should be considered before (A.) No electricity B. Maybe there is electricity C. Have electricity
28. What protective measures should be taken for the electrical equipment used in accordance with the relevant safety regulations?
A. No B. Protective zero or ground C. Antirust paint
29, in the process of electronic bottom plate soldering, shearing and other processes? (;).
A. Wear protective glasses B. Wear ear protectors C. Wear a hard hat
30. When workers are engaged in electrician operations, if they see the following signs, they indicate ().
A. Pay attention to safety B. Beware of cable C. Beware of motor injury
Second, fill in the blank question (2 points for each question, a total of 20 points)
1. Protection and zero connection refers to the interconnection of the part of the electrical equipment that is not charged under normal conditions with the power grid.
2. The protective grounding is to closely connect the parts of the ground voltage that may present a dangerous situation in the event of a fault.
3, the human body is a conductor, when the human body comes into contact with two different points, due to the role, it will form in the human body, this phenomenon is electric shock.
4. From the way the human body touches the charged body and the way the electric current passes through the human body, the electric shock can be divided into: the person standing on the ground or other conductor, a certain part of the human body touches the charged body; the human body touches the two-phase charged body at the same time; the human body is grounded Near the body, due to the stride voltage acting between the two feet.
5. The leakage protector can be used for protection and can also be used to supervise the insulation condition of the system or equipment; the line after the installation point of the leakage protector should be insulated, and the line should be well insulated.
6. Repeated grounding means that one or more places on the zero line are reconnected with the earth. The safety function is to reduce the voltage of the leakage equipment; to reduce the danger of the broken line; to shorten the duration of the shell or ground short circuit; Performance of overhead lines, etc. #p#分页头#e#
7. For places that are prone to static electricity, keep the ground, or lay a good ground; workers should wear clothes and shoes, and static electricity should guide the earth in time to prevent static electricity and sparks.
8. Static electricity has three major characteristics: one is high; the second is prominent; the third is serious.
9. The basic elements of electricity safety are,, and so on, are the basic elements for ensuring the safety of electricity. As long as these elements meet the requirements of safety regulations, the safety of electricity under normal conditions can be guaranteed.
L0, there are two types of current damage to the human body: that is, and.
Third, the judgment question (1 point for each question, a total of 20 points)
l In the environment full of flammable gas, manual power tools can be used. ()
2. When the household appliance is in use, the switch can be operated with wet hands. ()
3. In order to prevent electric shock, technical measures such as insulation, protection and isolation can be used to ensure safety. ()
4. For places where static electricity is likely to occur, keep the floor moist or lay a floor with good electrical conductivity. ()
6. In the buildings that are close to the line or the transformer, there may be signs of “no climbing, no electricity hazard†on the buildings that may be mistakenly climbed. ()
7. When someone has a low voltage electric shock, he should be pulled away immediately. ()
8. In places where it is wet or hot or has conductive dust, it should be powered by normal voltage. ()
9. When lightning strikes, if the operator is isolated in the exposed area and feels the hair is erected, he should kneel down immediately, bend forward, and hold his knees with both hands. ()
10. It is not necessary to turn off the power when cleaning the electric machine. ()
11. Usually, women's body impedance is greater than that of men. ()
12. There is no need to hang the nameplate on the surrounding columns of low-voltage equipment or pressure-resistant experiments. ()
L3, when the current is 100 mA, it is called lethal current. ()
14. When moving some non-fixed installation electrical equipment (such as electric fan, lighting), you do not need to cut off the power. ()1
15. The average resistance of an average person is 5000 to 7000 ohms. ()
16. When using hand-held power tools such as hand drills and electric grinding wheels, a leakage protector should be installed to ensure safety. ()
17. A fuse should be installed on the protection line of the lighting circuit. ()
18. For workers who work in places that are flammable, explosive, easy to burn and have static electricity, chemical fiber protective equipment () can be issued and used.
19. Power tools should be regularly inspected and repaired by an electrician with qualified documents ( )
20. The human body is electrocuted to death because the liver is seriously injured. ()
1. Under what circumstances should the switch and the operation handle of the knife gate be marked with the sign "No closing, someone working I " ?
2. What are the basic measures to prevent AC and DC electric shock?
3. What safety issues should I pay attention to when using electric drills or hand-held power tools?
Five, essay questions (10 points for each question, a total of 10 points)
What is the difference between protective grounding and protective zeroing?
Sixth, case questions (5 points for each question, a total of 5 points)
Liu Mei is an intern electrician in a company. She is learning a lot, but she still feels that she knows a lot.
So the master decided to test how much she knew. The master asked: "Do you know how much current is above the dead current?"
Liu Mei thought for a moment and said, "About 200 mAh." The master asked again: "What kind of lamps should be used for lighting in the tunnel pressure vessel?"
"Of course I know, I should use a high-quality general lighting." The master said: "Then you should say that the protection circuit of the lighting circuit should not be equipped with fuses?" Liu Mei said: "Of course, no, because this It will be wasted."
What is Liu Mei’s statement wrong? What is correct?
Answers to the electrical safety test questions 1. Multiple choice questions (1 point for each question, 30 points in total)
1. B2. C3. B4. C5. A6. C7. C8. B9. Al0. C
11. A 12. A 13. B14. Bl5. C16. Al7. C18. C19. C20. A
twenty one. A22. C 23. B 24. A 25. A 26. C27. C28. B29. A30. B
Second, fill in the blank question (2 points for each question, a total of 20 points)
1. Metal protection zero line 2. Conductive earth 3. Potential potential difference current 4. Single-phase electric shock two-phase electric shock stride voltage electric shock 5. Personal safety and low pressure to the ground
6. Grounding device is electrically shocked against lightning. Wet conductive anti-static accumulation 8. Voltage electrostatic induction tip discharge
9. Electrical insulation safety distance equipment and its conductor current carrying capacity is obvious and accurate sign l0. Electric shock and electric shock three, judgment questions (1 point for each question, a total of 20 points)
1. × (No, it will produce sparks, it is easy to cause an explosion) 2. × (cannot) 3. √4. √5. × (Ably absolutely, you must wear insulated shoes)
6. √7. × (First of all, to get him out of the power supply, you can use insulation to separate him from the power supply). × (should be powered by ultra low voltage)
9. √l0. × (To prevent the machine from accidentally starting to hurt people, you must turn off the power) 11. × (female body impedance is small)
12. × (The signboard must be hung with "stop, there is danger of electricity") 13. × (50 mAh) 14. × (The power must be turned off first)
L5. × (1000-l500 ohms) l6. √
17. × (No, otherwise the lighting appliance will short-circuit to the ground due to leakage, so that when the melt on the protection line is first blown, the metal casing of all electrical appliances will be charged, causing electric shock accident)
18. × (chemical fiber fabric is very easy to generate static electricity, can not be used) l9. √20. × (is the heart)
Fourth, short answer questions (5 points for each question, a total of 15 points)
1. Under what circumstances should the switch and the operation handle of the knife gate be marked with the label "No insurance iii 腥 � " ?
Answer: 1) Once the switch is closed, the switch and knife switch can be sent to the work place. 2) Discontinued equipment, once closed, may cause the risk of personal electric shock, equipment damage or the switch or knife that causes the total leakage protector to operate. 3) Once closed, the two power systems will be juxtaposed or cause a reverse power switch or knife switch.
2. What are the basic measures to prevent AC and DC electric shock?
Answer: Set the necessary protection for live equipment, and ensure that accidental contact and accidental access are prevented, so that it is impossible to contact; for accidentally charged equipment, measures such as protective grounding and protection to zero or installation of leakage circuit breakers should be adopted; Inspect, repair or test electrical wiring or electrical equipment. However, when it is necessary to carry out elective maintenance, appropriate personal protective equipment should be used. #p#分页头#e#
3. What are the safety issues to be aware of when using an electric drill or hand-held power tool?
Answer: (1) All conductive parts must have good insulation. (2) All wires must be tough and durable soft rubber threads. At the point where the wire enters the motor housing, a rubber ring is applied to protect the wire from abrasion. (3) The motor incoming line shall be equipped with a grounding or zeroing device. (4) In use, you must wear insulated shoes; wear protective gloves and other protective equipment. (5) Every time you use the tool, you must strictly check it.
Five, essay questions (each question lo points, a total of 10 points)
What is the difference between protective grounding and protective zeroing?
Answer: Protective grounding and protective zeroing are two technical measures to maintain personal safety. The differences are:
First, the protection principle is different. Low-pressure tide; ã æ° æ° îŠ¢é©¹î„¹ç¡Žçªæ‹— 驹硎çªæ‹— ┑缟璞 ┑缟璞 ┑缟璞 æ°ç¼ª æ°ç¼ª 蛊洳 蛊洳 蛊洳 î‚‹ î‚‹ î‚‹ î‚‹ î‚‹ î‚‹ î‚‹ î‚‹ î‚‹ î‚‹ î‚‹ î‚‹ î‚‹ î‚‹ ã ã ã ã ã缪 猓谀 猓谀 ┣æ¦é±¿ 褂 褂 褂 褂 ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã· ã·; Silly ãƒå–½æª îƒåˆ îƒåˆ îƒåˆ 媳 媳 媳 媳 媳 媳 媳 媳 媳 媳 媳 媳 媳 媳 媳 ã· ã· ã· ã·; The protective earthing is suitable for general low-voltage ungrounded power grids and low-voltage grounding grids with other safety measures; protective earthing can also be used for high-voltage ungrounded power grids. Ungrounded grids do not have to be protected from zero.
Third, the line structure is different. In addition to the phase line, the protective grounding system only has a protective ground wire. In addition to the phase line, the protection zero system must have a neutral line; if necessary, the protection zero line should be separated from the working zero line; its important device should also have a ground line.
Sixth, case questions (5 points for each question, a total of 5 points)
Liu Mei is an intern electrician in a company. She is learning a lot, but she still feels that she knows a lot. No, the master decided to test her and see how much she knows. The master asked: "Do you know how much mA or more of current is called lethal current? " Liu Mei thought about it: "About 200 mAh." The master asked: "In the tunnel pressure vessel, it should be used. What kind of lighting? " " I certainly know this, I should use ordinary lighting with large brightness." Master said: "You said that the protection circuit of the lighting circuit should not be equipped with a fuse? " Liu Mei said: "Of course not Because this will be wasted. â€
What is Liu Mei’s statement wrong? What is correct?
Answer: (1) The lethal current is 50 mA. (2) Illumination in tunnel pressure vessels, special low voltage lighting should be used. (3) The fuser should not be installed on the protection line, because when the lighting circuit is short-circuited due to leakage, the fuse on the protection line will be first blown, which will cause all metal casings to be charged, causing electric shock.
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