Lab 3: Kirchhoff’s Laws and Mesh and Nodal Analysis

Verification of Kirchhoff’s laws, mesh analysis and nodal analysis. Kirchhoff’s Voltage Law: The sum of all voltages in a loop is always yields zero. This concept is known as Kirchhoff’s voltage law or KVL. If we apply KVL to the circuit given below in this experiment, we get following equations. For 1st loop: -E1 +V1 +V2 = 0 …...……………………………………………………………….. (1a) For 2nd loop: - E2 +V2 +V3 = 0 ………………………………………………………………………. (1b) Kirchhoff’s Current Law: Kirchhoff’s current law states that the sum of currents entering in a node is always equal to the sum of current leaving that node. If we apply KCL to the circuit which is under observation in this experiment, we get the following equation. At node b: I1 + I3 = I2 .…….….…………………………………………………………………… (2a) Nodal Analysis: In an electrical circuit, a method is used for determination of voltages between nodes and this is known as nodal analysis. In this method, KCL is applied for finding current through all nodes. While for finding voltages, Ohm's law is used. Ground is taken as reference by convention. Mesh Analysis: In a planar circuit, a method named mesh analysis is used for finding currents at any place (loops) in the circuit. Where a circuit built on plane surface without crossing of 2 wires is named as a planar circuit. In mesh analysis, KVL is applied to find voltages through all loops. While Ohm's law is used for finding currents.