1, electrical neutrality: In the natural state, an object is usually neutral, that is, the number of positive charges and negative charges is equal, and the whole body does not show electricity. This is because the positive charge of protons and the negative charge of electrons are equal in number.
2. Like charges repel, like charges attract: when two objects have the same charge, they will repel each other; But when their charges are different, they will attract each other. This is because the interaction between charges follows Coulomb's law and shows the characteristics of mutual repulsion or attraction.
3. coulomb force: The interaction between charges at two stationary points is called electrostatic force, also known as coulomb force. Its size is directly proportional to the number of point charges and inversely proportional to the square of the distance between point charges. The direction of coulomb force can be described by electric field lines, from positive charge to negative charge.
4. Conductivity: Under the action of electric field, the free-moving charges of some substances will gather in a certain direction to form a current. This characteristic makes charge a carrier of current.
5. Relativistic invariance: the amount of charge has nothing to do with the state of motion, that is, under the condition of relativity, the law of conservation of charge still holds. No matter what reference frame is observed, the charge of charged particles remains the same.
Application of charge properties;
1. triboelectrification: an object can be charged by friction, and the charge on the surface of the object can be redistributed by the principle of electrostatic induction, so that the object can be charged with static electricity. For example, in industrial production, the principle of electrostatic induction can be used to remove impurities from materials.
2. Electroscope: An electroscope is an instrument for detecting whether an object is charged, which uses the mutual repulsion between charges to detect whether an object is charged with static electricity. For example, in an electronics factory, workers will use an electroscope to detect whether electronic components are charged, so as to ensure the quality and safety of products.
3. Electromagnetic induction: Electromagnetic induction is an important application of charge properties, which refers to the phenomenon that electromotive force will be generated in the conductor when the magnetic field changes, thus generating current. In power plants, generators are devices that convert mechanical energy into electrical energy by using the principle of electromagnetic induction.
4. Electric field and potential: Electric charge will generate an electric field, and every point in the electric field has a relative potential. Using this property, various electric field and potential measuring instruments can be made, such as electric field intensity meter and electrometer.
5. Electromagnetic wave: The nature of charge is also the basis for the generation and propagation of electromagnetic waves. Electromagnetic waves are generated by the vibration of electric and magnetic charges and can spread in space. Using this feature, people can manufacture various electromagnetic wave transmitting and receiving equipment, such as radar and radio communication.