"Household Electricity" Exploring Circuit PPT Courseware 3

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"Household Electricity" Exploring Circuit PPT Courseware 3

1. Activity 1: Understand the composition and connection methods of home circuits

Household wires, energy meters, main switches, fuse boxes, sockets, switches, and electrical appliances.

Self-introduction of "family members" in the family circuit:

Entry line:

I am the power source in the household circuit, supplied by the low voltage supply line, I have two members, one is called the live wire and the other is called the neutral wire. There is a voltage of 220 volts between the live wire and the ground, there is no voltage between the neutral wire and the ground, and there is a voltage of 220 volts between the live wire and the neutral wire.

Meter

Measuring and recording the amount of electricity used by the user, and its installation and maintenance are not within the user's rights. There are 4 binding posts from left to right, 1 and 3 are connected to the household line.

Knife switch

In household circuits, it can control the on and off of all electrical appliances.

2. Observe the three-wire plug and three-wire socket

How is the three-wire socket connected to the circuit?

Thinking: Both are leaking electricity, why is the contrast so big?

When an electrical appliance leaks electricity, there is a voltage of 220 volts on its metal shell. If the electrical appliance does not have a grounding wire, when a person touches it, current will flow through the human body into the earth, causing an electric shock. If the shell is grounded, current will enter the earth through the ground wire. When the human body touches the shell of the electrical appliance, no current will flow through the human body. Therefore, the ground wire is the safety wire of electrical appliances.

3. Test pen

Your hand must touch the metal electrode at the end of the pen and never touch the metal on the tip.

Correct operation:

Touch the metal body at the tail of the pen with your hand; the neon tube emits light when the metal body of the pen tip touches the live line, but does not light up when it touches the zero line.

Wrong operation

The neon tube will not emit light even if the metal body of the pen tip touches the live wire without touching the metal body at the end of the pen.

Why does the neon tube glow when the hand touches the metal body at the end of the pen, but people don't get electric shock?

Because when the pen tip touches the live wire, a voltage of 220 volts is applied to the series circuit formed by the test pen and the human body. The current passing through the neon tube and the human body is less than 220 volts/1000000 ohms = 0.00022 amperes = 0.22 milliamperes. This current can make the neon tube glow. , but it is not harmful to the human body.

practice

1. A main switch, energy meter and fuse should be installed in the home circuit from the entrance line to the electrical appliances. The correct order of installation ( )

A. Electric energy meter, main switch, fuse

B. Knife switch, energy meter, fuse

C. Knife switch, fuse, energy meter

D. Fuse, main switch, energy meter

2. Which of the following is correct about the use of electricity test pens ( )

3. In the home circuit, which of the following installation errors is ( )

A. Light bulbs should be connected in parallel

B. Series connection between socket and light

C. The switch is connected in series with the controlled electrical appliance

D. Fuses are connected in series in the circuit

Keywords: Exploring Circuit Teaching Courseware, Home Electricity Teaching Courseware, Shanghai Science Edition 9th Grade Physics PPT Courseware Download, 9th Grade Physics Slide Courseware Download, Exploring Circuit PPT Courseware Download, Home Electricity PPT Courseware Download, .PPT format ;

For more information about the PPT courseware "Exploring Circuits and Household Electricity", please click the "Exploring Circuits ppt Household Electricity ppt" tag.

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Update Time: 2024-10-08

This template belongs to Physics courseware Shanghai Science Edition Ninth Grade Physics industry PPT template

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