"Safe Use of Electricity" PPT courseware

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"Safe Use of Electricity" PPT courseware

Part One: Review before class

There are two wires in a household circuit, one is called the ______ wire and the other is called the ______ wire. There is a voltage of ______ volts between the live wire and the neutral wire, and a voltage of ______ between the neutral wire and ground.

The low-voltage power supply line is connected to the household circuit through ______ ______ ______.

Each lamp in the household circuit should be connected ______, the switch should be connected ______ with the light it controls, the socket and the lamp should be connected ______, and the fuse box and the electrical appliance should be connected ______.

The application of electric energy promotes the progress of human society and brings convenience to people's lives. However, if we do not pay attention to the safety of electricity use, it will cause danger to life and property losses.

PPT on the safe use of electricity, part 2: electric shock accidents

1. Electric shock refers to an injury accident caused by a certain intensity of current flowing through the human body.

Question 1: Will people get electric shock as long as there is current passing through the human body or there is voltage across the human body?

Question 2: When two hands touched the positive and negative terminals of a dry battery, why did no electric shock accident occur?

Question 3: According to Ohm's law, what does the current in a conductor depend on? What determines the size of the current passing through the human body?

2. The size of the current passing through the human body is determined by: the external voltage and the human body's own resistance.

Question 4: Do different people have the same resistance? Is the resistance the same for the same person at different times?

Question 5: So, what is the safe voltage value for the human body?

PPT on the safe use of electricity, part three: first aid measures for electric shock

1. Cut off the power immediately

(1) First, cut off the power supply, or use a dry wooden stick to spread the wires, and quickly remove the person who was electrocuted from the power supply (never touch the person who was electrocuted directly).

(2) When a fire occurs, the power supply must be cut off first to carry out fire-fighting operations.

2. Emergency rescue

(1) If the person is seriously electrocuted, artificial respiration is required.

(2) Send to hospital.

PPT on safe use of electricity, part 4: common sense on safe use of electricity

Principles for safe use of electricity:

Do not come into contact with low-voltage charged objects

Not close to high-voltage charged objects

What should we pay attention to in life?

(1) Be careful to prevent contact with live metal. When inserting the plug into the power supply, do not touch the metal pins with your hands.

(2) Keep the insulation part dry and do not touch the switch with wet hands.

(3) Do not fly kites near high-voltage lines.

(4) For household appliances with metal casings, the casings must be grounded.

(5) Iron wires cannot be wrapped around wires, and clothes cannot be dried on wires.

(6) When someone gets an electric shock, first cut off the power supply, or use an insulator such as a dry wooden stick to open the wires.

(7) When setting up the antenna, be careful not to touch the wires.

PPT on safe use of electricity, part 5: summary

1. The voltage that is safe for human body use is: no higher than 36V. In humid environments, safe voltage should be 24 volts or even below 12 volts.

2. Forms of electric shock:

"Low voltage electric shock" single line electric shock, double line electric shock

"High-voltage electric shock" arc electric shock, step voltage electric shock

3. First aid methods for electric shock

(Turn off the power, use a dry wooden stick to remove it, and then perform artificial respiration, etc.)

4. Principles of safe electricity use:

Do not come into contact with low-voltage charged objects.

Not close to high-voltage charged objects;

Safe use of electricity PPT, Part 6: Practice

1. Under normal circumstances, voltage below ____ volts is safe. But in a humid environment, the safe voltage should be ____ volts or even below _____ volts.

2. In household circuits, electric shock is caused by direct contact with ______. The principle of safe use of electricity is: do not contact ___________; do not approach ___________

3. Question: The human body gets an electric shock when it comes into contact with a 220V bare wire, but a bird stands with its two feet on a high-voltage bare wire and is fine. Why is this?

A. Birds have low resistance

B. Birds do not conduct electricity when they are dry

C. The bird's two feet are on the same line, and the voltage is very small.

D. Birds are small in size

Analysis: Humans and birds are both conductors. People standing on the ground and coming into contact with 220V live wires will cause electric shock accidents. The voltage on high-voltage wires refers to the voltage between two high-voltage wires or between high-voltage wires and the ground. Birds stand with two feet on the same wire. The high-voltage lines are very close together and the voltage is very small, so there is no chance of electric shock.

Keywords: Zhejiang Education Edition eighth grade science PPT courseware for the second volume free download, safe use of electricity PPT download, .PPT format;

For more information about the "Safe Use of Electricity" PPT courseware, please click the "Safe Use of Electricity ppt" tab.

"Safe Use of Electricity" PPT download:

"Safe Use of Electricity" PPT download Part 1: Electric shock and the danger of electric shock. The human body is a conductor. When voltage is applied to the human body, current will flow through the human body. When the current passing through the human body is very small, people do not feel it; when the current passing through the human body is slightly larger, people...

"Safe Use of Electricity" PPT:

"Safe Use of Electricity" PPT Part One Content: Classroom Experience Experience: Connect the positive and negative terminals of two dry batteries with your hands, experience it and talk about your feelings. Analyzing the data in the table, it can be concluded that the current passing through the human body _______, and the degree of harm caused is also _______. Notice..

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Update Time: 2024-11-06

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