Introduction

The seventeenth century was the century for theorization of electricity. The electrical technology became more and more advanced and complex. Direct current technology was dominating the new inventions. It was very necessary to mathematize the different parameters of these complex electrical connections and circuits. We had to develop a new mathematical model to calculate and determine the voltage, current power etc. of a circuit at different branches and nodes without measuring it directly. Some important theorems regarding electrical circuit were mutated during the last half of the century. These theorems work good with some constrain in the nature of the circuit. Before the semiconductor circuits or electronic circuits came into the picture these theorems were successfully used to determined different parameters of an electrical circuit. In this chapter let us find out and discuss about some of those electrical circuit theories.

Basic Concepts: Electric Circuit, Loop, Mesh etc.

• a. Electric circuit: An electric circuit or electric network is a combination of different electric components (discussed in the next topic) via loop and branches of conductors.

• b. Node: A node is a junction of an electric circuit where two or more circuit components are connected together.

• c. Branch: Branch is the part of the circuit which lies between two junctions or nodes in an electric circuit.

• d. Loop: Loop is the closed path in an electric circuit in which no element or node is connected more than once.

• e. Mesh: Mesh is such a loop that does not involve no other loop in it. So every mesh is a loop but all loops are not meshes.