Basic understand of Electronic & Electrical laws

Ohm’s law: It states that, the electrical current flowing through a conductor material is directly proportional to the voltage difference between the ends of the conductor material, keeping the physical conditions unaltered.

                                       So,

                                                   I proportional to V

Where, I= electric current flowing through conductor material,

           V= voltage difference between the ends of the conductor material.

                                                 Or, V/I=constant

This constant is known as resistance of the conductor material and is denoted by `R’.

                                                    V/I=R

Law of Resistance: This law states that the resistance of a conductor material is directly proportional to the length of the conductor, inversely proportional to the cross-section of the conductor and depends upon the nature of the conductor material at constant temperature.

                 Now we can say that, R =p. l/a

                 Where R = resistance of the conductor material

                              l = length of the conductor material

                              a= cross-section area of the conductor material

                              p= specific resistance or resistivity of the conductor material.

Kirchoff’s law: When the electrical networks cannot be solved by ohm’s law, then we take help to different laws and theorem to save time and to reduce mathematical calculations.

Kirchoff’s laws comprise of two laws: (1) Current or point law and (2) Voltage or mesh law.

Current or point law: It states that the algebraic sum of the currents meeting at a point in an electrical circuit is always zero.

This law proves that the incoming current = outgoing current

Voltage or mesh law: It states that, in any closed part of an electric circuit, the algebraic sum of the E.M.F is equal to the algebraic sum of the products of the resistances and currents flowing through them.

Coulomb’s law: The electric force attraction or repulsion between two point charges is directly proportional to the product of two charges and inversely proportional to the square of the distance between them. The force acts along the line joining the two charges and its value depends upon the nature of the intervening medium.

Explain: Let us consider two point charges q₁ and q₂ separated by a distance r, then from Coulomb’s law, the electric force F between the two charges in vacuum is given by,

F proportional q₁. q₂/r²

Where ε₀ be the permittivity of vacuum

Where 1/4 π ε₀ = 9×10⁹ Nm²C⁻²