The electric field is a physical object which can carry both momentum and energy. Coulombs law states that force exerted between two point charges. It is the net charge enclosed in the surface that matters in gausss law but the total flux of electric field e depends also on the surface chosen not merely on the charge enclosed. Electrostatics class 12 and iitjee summary pdf download. Electrostatic phenomena arise from the forces that electric charges exert on each other and are described by coulombs law. Is directly proportional to product of magnitude of the two charges. Consider twopoint charges q 1 and q 2 separated by a distance r.
On the other hand, one may show that the gravitational force is only. Cbse ncert notes class 12 physics electric charges fields. Coulombs law states that the magnitude of the electrostatic force between two point charges is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between them. Even though electrostatically induced forces seem to be rather weak. The electrostatic force between the two particles is approximately. In physics, electrostatics deals with the phenomena and properties of stationary or slowmoving electric charges. Derivation of coulombs law of electrostatics from gausss law.
Draw a gaussian surface ofsphere of radius r with q 1 as centre. The electric field at the point q due to q is simply the force per unit positive charge at the point q. So if you have information about distribution of electric charge inside the surface you can find electric flux through that surface using gausss law. E must be normal tothis surface and must have same magnitude for all pointson the surface. Coulombs law 3 let us consider two pointlike electric charges q and q at position x 1 and x 2, respectively. When more than two charges are present, the net force on any one charge is simply.