Who has a detailed explanation of the typical example problems at the review syllabus level of the c

It is not necessary to do many questions, but to focus on the understanding and mastery of knowledge, so as to be able to respond to all changes with the same. Hope it helps.

You have to answer for yourself and seek truth from facts

1.ChargeCharge, also called electricity, is a property of matter.

There are only two types of electric charges: positive and negative. The charge that is the same as that of the glass rod rubbed by silk is called a positive charge; The charge that is the same as that of the rubber rod that has been rubbed against the fur is called a negative charge.

The same charge repells each other, and the different charges attract each other.

A charged body has the property of attracting small and light objects The amount of charge is called the electric charge.

Electroscope: An instrument used to test whether an object is electrically charged, and works according to the principle of mutual repulsion of the same charge.

1.The directional movement of the charge forms an electric current (the direction of the directional movement of free electrons in a metallic conductor is opposite to the direction of the current), and the directional movement of the positive charge is specified as the direction of the current.

2. The ammeter cannot be directly connected to the power supply.

3.Voltage is the cause of the formation of current, the safety voltage should not be higher than 36V, and the home circuit voltage should be 220V.

4.The resistance of a metal conductor increases with temperature (the higher the temperature of the glass, the smaller the resistance).

5.An object that can conduct electricity is a conductor, and an object that cannot conduct electricity is an insulator (false, "easy", "not easy").

1. Positive charge: The charge carried by the glass rod rubbed by silk is called positive charge.

2. Negative charge: The charge on the rubber rod that has been rubbed by the fur is called negative and positive charge.

The law of charge action: the same charge repells each other, and the different charge attracts each other.

Electroscope: Structure: metal balls, metal rods, metal foils. Purpose: To check whether the object is charged or not.

Voltage (u): Voltage is what causes the formation of current in a circuit, and a power supply is a device that provides voltage.

SI units: volts (v); Commonly used: kilovolts (kv), millivolts (mv).1 kV = 103 V = 106 mV.

The instrument for measuring voltage is: voltmeter, rules of use: voltmeter should be connected in parallel in the circuit; The current to be from"+"The binding post enters, from"-"Binding post out; The measured voltage should not exceed the range of the voltmeter;

There are two ranges of voltmeters commonly used in laboratories: 0 3 volts, and the voltage value represented by each small cell is volts;

0 15 volts, the voltage value represented by each small cell is volts.

Memorized voltage: 1 volt of dry cell battery; The voltage of 1 lead-acid battery is 2 volts; The home lighting voltage is 220 volts; The safety voltage is: not higher than 36 volts; Industrial voltage 380 volts.

The above is the second junior high school network, I have sorted out the third junior high physics, electrical part of the circuit knowledge points.

Chapter 8 Electric Power Review Syllabus.

1. The process of generating electrical energy is the process of transforming energy into energy.

In the process of using electrical energy, energy is converted into energy.

2. Calculation formula: w= =

3. Units. 4. Measure the electric energy meter.

Category, Definition: ;

2. Significance: ;

3. Units and symbols kw= w

4. The formula "p==."

6. Measure the small lamp.

The electrical power of the bubble.

There are several ways to do this).

7. Electricity and heat.

1. The composition of the home circuit: 、

2. The connection of the home circuit is not connected.

3. Live line and neutral line.

4. a fuse.

5. Causes of combustion and trapping of excessive current in the circuit: ;

6. a socket. 7. a voltage tester.

8. Types of bulbs.

9. Electric shock. 10. Common sense of safe use of electricity:

11. First aid methods for electric shock: .