The Basic Laws of Electric CircuitS (cont.)

Welcome back guys, this topic now is the continuation of the basic laws of electric circuit. Since the elements of an electric circuit can be interconnected in several ways, we need to also to understand some basic concepts of network topology. In network topology, we study the properties relating to the placement of elements in the network and the geometric configuration of the network.

| NODES, BRANCHES, AND LOOPS |

What are these Nodes, Branches, and Loops ?

Branch

        - a branch represents a single element such as a voltage source or a resistor.

In other words guys, a branch represents any two-terminal element. The circuit in Figure has five branches, namely, the 10-V voltage source, the 2-A current source, and the three resistors.

Node

        - a node is the point of connection between two or more branches.

A node is usually indicated by a dot in a circuit. The circuit in Figure has three nodes a, b, and c. Notice that the three points that form node b are connected by perfectly conducting wires and therefore constitute a single point. the same is true of the four points forming node c.

Loop

       - a loop is any closed path in a circuit.

A loop is a closed path formed by starting at a node, passing through a set of nodes, and returning to the starting node without passing through any node more than once.

| KIRCHHOFF'S LAWS |

What is Kirchhoff's Current Law ?

               - KCL or Kirchhoff's Current Law states that the algebraic sum of currents entering a node ( or a closed boundary ) is zero.

Mathematically, KCL implies that 

where N is the number of branches connected to the node and (i sub k) is the nth current entering (or leaving) the node. By this law, currents entering a node may be regarded as positive, while currents leaving the node may be taken as negative or vice versa.

here is one of example on how the KCL solves.

i1 + (-i2) + i3 + i4 + (-i5) = 0

since currents i1, i3 and i4, are entering the node, while currents i2 and i5 are leaving it. By rearranging the terms, we get

i1 + i3 + i4 = i2 + i5

The sum of the currents entering a node is equal to the sum of the currents leaving the node.

What is Kirchhoff's Current Law ?

  - state that the algebraic sum of all voltages around a closed path (or loop) is zero.

expressed mathematically, KVL states that

where k is the number of voltages in the loop (or the number of branches in the loop) and V sub k is the kth voltage.

For example, in the figures we branch 3, the positive terminal is met first; hence we have +3. For branch 4, we reach the negative terminal first; hence, -v4. Thus, KVL yields

-v1 + v2 + v3 - v4 + v5 = 0

rearranging terms gives

v2 + v3 + v5 = v1 + v4

which may be interpreted as

Sum of voltage drops = Sum of voltage rises

| My Learning Experience XD |

This week I learned that in a circuit there's also an element which may interconnected in several ways, these are Nodes, Branches, and Loop. I learned also that on how to group each elements with help of sir Jay. I learned also The Kirschhoff's Law. In Kirschhoff's Law there are two law they are Kirschhoff's current Law and Kirschhoff's voltage Law. Sir jay also taught as on how to solved the problems of these two laws.