【 Weak current College 】 safe use of electricity and architectural lighting-class exercises

First, multiple choice questions (alternate answer each question, only one adresses. ）
1. the proprietor is () the following voltage.
A．220V
B．110V
C．36V
D．12V
　　　
2. adoption of the current in the human body () or more, you will have difficulty breathing, muscle spasms, or even fatal accident occurred.
A．100mA
B．60mA
C．500mA
D．30mA
　　 　
3. for the purpose to prevent electric shock as protector of the use of () 's protector.
A £ ® action time 0.1s, current 30mA
B £ ® action time 0.1s, current 15mA
C £ ® action time 0.5s, current 30mA
D £ ® action time 0.5s, current 30mA
　　 　
4. a first class range of lightning lightning protection for buildings with roller ball method determines, in its protection RADIUS is ().
A．30m
B．45m
C．60m
D．100m
　　 　
5. the second type of lightning lightning protection for buildings with roller ball method scope for determining the radius of its protection is ().
A．30m
B．45m
C．60m
D．100m
2. fill in the blanks questions (please toyoko line on enter your answer. 1. the shock is) the human body caused by the accidental exposure or personal injury accidents.
2. in accordance with human touch charged body approaches and current passes through the body, electric shock can be divided into, and causition.
3. the common voltage safety ratings have 36V, and.
4. install lighting circuits, switches and sockets generally are not below the ground. If necessary, the socket can be loaded low, but may not be lower than the ground.
5. the commonly used methods and electric shock treatment.
6. in order to prevent accidental electrocution accident, the commonly used measures of protection, and grounded.
7. in order to prevent electric shock for the purpose of the leakage current protective device, to choose the action within the time-s, using current mA's protector. Third, the noun parser (in the the nouns in the text box below, enter your answer. 1. protective earth)
　　　 　
2. zero protection
　　　 　
3. the first category of civilian buildings of lightning protection
IV. question
1. current to human harm and what factors? 【 answer points 】--------------------------------------------------------------------------------① by volunteers current value.
② the human resistance values.
③ current passes through the body the length of time.
④ current flows through the human body.
⑤ current of frequency and voltage of electric shock. --------------------------------------------------------------------------------

2．雷电的破坏作用是如何引起的？【答题要点】 --------------------------------------------------------------------------------
Lightning damage has two types of lightning directly stroke on buildings, Lightning by high temperature may cause burning buildings, and lightning current channel, the body of water heating, vaporization expansion and strong mechanical damage to buildings, this is called direct leiguo voltage or lightning. Another is the lightning caused by electromagnetic induction electrostatic induction or overvoltage is called induced voltage or lightning.
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3. building mine what measures should be adopted? 【 answer points 】--------------------------------------------------------------------------------① measures against lightning, is based on the installation of various forms of jieshan qi.
② Lightning measures, notably the building residual induction charge rapidly introduced into the Earth, and often used method is to be used for reinforced concrete roof down lead and earthing connection.
③ lightning protection measures wave invasion, basic protection measures is in the high-voltage power line surge arresters for client-side installation. --------------------------------------------------------------------------------

4.雷电是如何形成的？【答题要点】 --------------------------------------------------------------------------------
Lightning is a thundercloud or between the discharge Earth thundercloud. Intensive Earth over the water mist is often referred to as cloud. Clouds in the lower and upper air friction collision of a strong, positive or negative charge with, with charge of cloud is called a thundercloud. Thundercloud discharge phenomenon called lightning phenomenon. When thundercloud charge accumulated more and make it around the electric field intensity up to a certain extent, it will breakdown the air insulation to thundercloud or thundercloud and Earth, between discharge, because the temperature of the discharge 26000 ° c, air heating rapid expansion, strong arc light and sound, this is the lightning and Thunder.
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5. the building and installation of electrical facilities to the lightning protection system which kind? how to layout? 【 answer points 】--------------------------------------------------------------------------------① jieshan qi. Including the lightning rod, galvanized round steel or galvanized steel pipe, its top processing into sharp shape, the lower the grounding wire welding with earthing devices; lightning conductor, also known as overhead lines, is suspended at a height of grounding line. Lightning belt, is a prominent position at the top of the building along the edge of the laying of the metal band as jieshan Qi, and good connections with the Earth. Lightning network, is the use of reinforced concrete structure reinforcement mesh for lightning protection.
② down lead. Connection jieshan Qi and grounding of metal conductors.
③ grounding device. Through down lead and the Earth as a good electrical connection of the device. --------------------------------------------------------------------------------

6. electrical equipment grounding, zero protection principles and requirements of? 【 answer points 】--------------------------------------------------------------------------------
Ground fault protection is normally not live, but in the failure case possible dangerous voltage parts closely connected with the Earth. Ground fault protection due to leakage device-to-ground voltage main decisions to protect Earth resistance Rb size, as long as proper control of the size of the Rb, that is, you can limit the residual current device-to-ground voltage within the security.
Zero protection is the electrical equipment in normal circumstances not live metal parts and the grid of the zero line closely connected. Zero protection suitable for neutral earthing system, when a certain phase live parts touch even the device shell, the shell formation through the device line for zero line of single-phase short-circuit (the touch shell short circuit), short-circuit current Id spur line protection device for rapid action, thus bringing fault partially broken power, eliminating the risk of electric shock. --------------------------------------------------------------------------------

7. accidental electrocution of what kind of forms? what are the characteristics of the? 【 answer points 】--------------------------------------------------------------------------------
The body of the main forms of electric shock accident described below.
① single-phase electric shock, characterized by human touch a phase charged body of electric shock accident. Their risk level and whether the ground for neutral point. Neutral grounding system single-phase electric shock than neutral system of risk.
② two-phase electrocution, characterized by the body's two simultaneous touches the two-phase charged body of electric shock when the human body is the line voltage 380V.
③ causition, features when live equipment grounding, the current in the place of surrounding soil in the voltage drop. The human body in place around due to electric shock accident. In the vicinity of high voltage-high ground potential, the farther away the potential Earth point. --------------------------------------------------------------------------------

8.如何防止触电事故的发生？【答题要点】 --------------------------------------------------------------------------------
Prevent electrocution accident should note the following.
① to judge whether the wire or equipment, must be used on live electrical equipment (or pencil, etc.), must not be allowed to touch by hand.
② in repairing electrical equipment or replace the melt, cut off power supply and switch on "at closing" brand is strictly prohibited.
③ When installing lighting circuits, switches and sockets generally not below ground 1.3m. If necessary, the socket can be loaded low ground, but should not be lower than 15cm.　　Do not use wet hands touch switches, sockets, lamp holders, etc, do not use the wet cloth to wipe the bulb. Inside wiring is the prohibition of the use of bare wire and insulation damage wire to wire, Plug and socket damage, must be replaced in a timely manner. Plastic sheath cable connections should be junction box. Plastic covered wire strictly prohibited or other conductors direct burial in cement or lime paint layer.
> ④ in power line nearby, do not install the antenna on the radio, TV set, not a kite. Do not use the live equipment around steel ruler. Replace the fuse is strictly prohibited to use copper wire.
⑤ found wires or electrical equipment fire, should quickly cut off the power, in a charged state, must not use water or foam extinguisher.
⑥ Lightning days try not to go out; don't rain under the big tree retreat or stand on the height, but should be in place at the low-lying and try to keep the feet. --------------------------------------------------------------------------------

9.安全用电的措施主要有哪些方面？【答题要点】 --------------------------------------------------------------------------------
Safe electricity measures include:
① use voltage safety;
② Select proper protective equipment;
③ electrical device shell ground protection, protection of the neutral and earth leakage protection. --------------------------------------------------------------------------------

10. when we encounter electric shock accident should be how to help themselves and each other? 【 answer points 】--------------------------------------------------------------------------------
① self-help. When his shock and sober, first of all to remain calm, wrestled power, transfer to a safe place, in case of voltage electric shock when you step to prevent falling, falls, etc. second injury accidents.
② aid. For others, electric shock, the first step is to shock people out of power, such as brake, power failure or an electric shock, away from the power supply, etc. Specific methods are as follows. Rapid brake or unplugging the power plug, if unable to find a power switch or distant, insulated tools to cut, cut off or drop it off power cord.
Quickly use insulated tools, such as dry bamboo pole, a stick reopened the conductor electric shock, or electrical appliances.
Station in dry wood, clothing, and so on insulator, insulated gloves or wrapped drying clothing pull wires, electrical equipment or electrical shock.
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