The formula for determining the electric field intensity e is Coulomb's law, and its mathematical expression is:

E = k * (Q / r^2)

Among them,

E stands for electric field strength, and the unit is Newton/Coulomb (N/C). K stands for Coulomb constant, and its value is about 9 *109N m 2/c 2. Q stands for the amount of charge in coulombs (C). R represents the distance from the charging point to the observation point in meters (m).

According to Coulomb's law, the electric field intensity is directly proportional to the charge Q and inversely proportional to the square of the distance R. In other words, the greater the charge, the greater the electric field intensity. The farther the distance, the smaller the electric field intensity. This formula describes the action between charges, that is, the action of electric field force on surrounding charge points.

Application of electric field intensity;

1, electrostatics

The intensity of electric field is the embodiment of electrostatic force, which is used to describe the interaction between charges. In electrostatics, the intensity of electric field can be used to calculate the force of charge, the distribution of charge and the shape of electric field.

2. Electric field potential energy

The intensity of electric field is related to the distance between charges and the amount of charges, which can be used to calculate the potential energy of charges in the electric field. The potential energy of electric field plays an important role in the movement and storage of charge.

3, electric field induction and shielding

The electric field intensity can induce the charge near the charged body, thus causing the charge distribution and motion of other objects. This induction phenomenon has important applications in electrostatic adsorption, electromagnetic induction and other fields. The free movement of electrons in conductors such as metals can shield the electric field intensity. This shielding effect has important applications in electromagnetic wave protection and electronic equipment shielding.

4, incentive and control

By changing the electric field intensity, the movement of electronic equipment can be excited and controlled. For example, in an electron microscope, the intensity of an electric field can be used to control the focusing and deflection of an electron beam.

6. Biomedical applications

Electric field intensity has many applications in biomedicine, such as electrical stimulation therapy, electrophysiological measurement and electrophysiological research.