1. Ohm’s Law:
These electrical theorems are applied to the electrical network to simplify and to find the solution of the electrical network.
The voltage across a resistance is equal to the product of the resistance and the current flowing through it.
Voltage = Resistance × Current.
2. Kirchhoff’s Laws:
These laws are more comprehensive than the Ohm’s law and are used for solving electrical networks which may not be readily solved. It is mainly useful in determining the equivalent resistance of a complicated network of conductors and for calculating the currents flowing in the various conductors.
It states that "In any electrical network, the algebraic sum of the current meeting at a point (or junction) is zero".
Meaning: It simply means that the total current leaving a junction is equal to the total current entering that junction.
Incoming current = Out going current.
The algebraic sum of the product of currents and resistance in each of the conductors in any closed path (or mesh) in a network plus the algebraic sum of the EMF in that path is zero.
Meaning: It simply means that, if we start from a particular junction and go round the mesh till we come back to the starting point, then we must be at the same potential with which we started.