Atoms concepts

Electrons and protons are found in atoms of any substance. A neutral body contains charges of opposite sign which are equal in absolute value. Electric charges are said to be point charges if the linear dimension of the bodies on which the charges are concentrated are very much smaller than any other lengths pertinent to the problem under consideration.

Coulumb's law

Coulomb's law states that the force F of electrostatic interaction between two point electric charges q1 and q2 in a vacuum is directly proportional to the product of the charges and inversely proportional to the square of the distance r between those charges.

Law of conservation of electric charge

The law of conservation of electric charge states: the algebraic sum of the electric charges remains constant in a closed system. The electric charge of any body consists of a whole number of elementary charges each of which equals 4.8* 10^-10 electrostatics units of the quantity of charge. The smallest stable sub atomic particle having a negative elementary charge is called the electron.

Electrostatics

Electrostatics is the study of properties and interaction of electric charges which are fixed with respect to the inertial frame of reference chosen for the study. There are two kinds of electric charges: positive and negative. Like charges repulse each other; unlike charges attracts each other.

zone of hydrodynamic stabilization

In the flow of an incompressible fluid through a cylindrical pipe, the stream in the initial part of the pipe consists of two portions: the boundary layer at the wall and the undisturbed velocity core, within whose limits the fluid velocity is same for all points of the given cross section. The thickness of the boundary layer gradually increases with the distance from the pipe inlet until at a distance l slab, the boundary layer fills the cross section of the pipe. The initial zone of length l slab is called as the zone of hydrodynamic stabilization.

Boundary Layer

At very large values of the Reynolds’s number it can be assumed with some approximation that the effect of viscosity is manifested only in the portion of the fluid that flows in the immediate vicinity of the surface of the body it is flowing around. This portion of the fluid is therefore called the boundary layer. The fluid velocity at the surface of the body equals zero the velocity at the outer limit of the boundary layer depends upon the velocity and transverse dimensions of the oncoming stream and the shape and size of the body. The thickness of the boundary layer gradually increases as the layer moves downstream along the surface of the body. Other conditions being equal the greater the Reynolds’s number the thinner the boundary layer.