Positive charge and negative charge. In physics, it is stipulated that a glass rod rubbed with silk is positively charged, and a rubber rod rubbed with fur is negatively charged.

Like charges repel each other and dissimilar charges attract each other

definition

reason

Nature

The physical quantity that represents the amount of charge is represented by q. The unit is Coulomb, referred to as Coulomb, symbol C. Positive charges have a positive charge, and negative charges have a negative charge.

When a charged object is close to a conductor, due to the mutual attraction or repulsion between charges, the free charges in the conductor will move toward or away from the charged object, so that the end of the conductor close to the charged object has a different kind of charge, and the end far away from the charged object has the same kind of charge. This phenomenon is called electrostatic induction.

The interaction between charges and the free movement of charges in a conductor

The process of using electrostatic induction to charge metal conductors is called induction charging. For example, if you keep the charged object c still, use an insulating tool to separate conductors a and b, and then remove c, then a will be negatively charged and b will be positively charged.

Charge is neither created nor destroyed, it can only be transferred from one object to another, or from one part of an object to another; during the transfer process, the total amount of charge remains unchanged.

A system with no charge exchange with the outside world, the algebraic sum of charges remains unchanged

Any charged phenomenon cannot violate the law of conservation of charge. No matter which kind of electrification process, there is no creation or destruction of charge. Its essence is that the charge has been transferred, that is, the electrification process is the redistribution process of the charge carried by the object.

The smallest amount of charge is called the elemental charge. Represented by e

First measured by American physicist Millikan

①The elementary charge is not an electron or a proton. The amount of charge carried by electrons and protons is equal to the elemental charge.

②The amount of charge is a physical quantity that cannot change continuously. The amount of charge of all charged objects is an integer of e. times.

③Elemental charge is not a unit and has no electrical properties. It is just the smallest electric charge. load.

The ratio of the charge e of the electron to the mass m of the electron