This document discusses Thevenin's theorem. It begins by introducing the theorem, stating that it can simplify complex circuits into an equivalent circuit of a voltage source in series with a resistor. It then provides the steps to use Thevenin's theorem: 1) remove the load, 2) calculate open circuit voltage, 3) calculate internal resistance, and 4) redraw the circuit with the load reconnected. Finally, it lists some limitations of the theorem, such as it not applying to nonlinear or magnetically coupled circuits.

1. THEVENIN'S
THEOREM
MEMBERS NAME
▪ KALPANA TIWARI
▪ RITIKA GUPTA

2. CONTENT
❑ INTRODUCTION
❑ WHAT IS THEVENIN'S
THEOREM?
❑ STEPS TO SOLVE THEVENIN'S
THEOREM
❑ LIMAITATION OF THEVENIN'S
THEOREM

3. INTRODUCTION
 • Thevenin’s Theorem is a very important and
useful theorem.
 • It is a method for the reduction of a portion of a
complex circuit into a simple one.
 • It reduces the need for repeated solutions of the
same sets of equations.

4. WHAT IS THEVENIN'S THEOREM?
 "The Thevenin Theorem explains how to simplify a complex circuit. It states that any
linear circuit with only voltage sources, current sources and resistors can be simplified to
a voltage source with a series resistor".
 But what does this really mean?
 Sometimes a picture says more than thousand words, so here are two pictures to explain what
Thevenin’s Theorem is about.
 This circuit……
 …can be represented by this simple circuit

5. STEPS TO SOLVE THEVENIN'S
THEOREM
 This is the circuit to explain Thevenin's theorem. Thevenin's theorem can be
explained with the help of the following simple example. The steps are as follow:
 Step 1: Load resistance (RL) remove from the circuit terminal a and b for
the network shown in fig. 1.82.
 Step 2: The open circuit voltage (voc) which appear across terminal a an b
in fig. 1.82(a) is calculated as
Voc is called the "Thevenin's voltage" (VTH).

6. Step 3: Removing the battery from the circuit leaving the
internal resistance (r) of the battery behind it (in fig.) when
viewed from terminals a and b , the internal resistance of the
circuit is given by
This resistance Ri is called Thevenin's
equivalent resistance (RTH).
Step 4 : Thevenin's equivalent circuit is drawn as shown
in (in fig) and RL is reconnected across terminals a and b.
The current through RL is

7. LIMITATION OF THEVENIN'S THEOREM :
1. Thevenin Theorem is not applicable to the circuits that contain
nonlinear elementslike transistors and diodesetc.
2. It is not applicableto the circuits having unilateral elementslike
diodeetc.
3. Thevenin'sTheoremcannot be used for the circuits that contain
magnetic coupling between load and any other circuit element.
4. It is Not possibleto apply the Thevenin'stheorem to the circuits
containing load in series or parallelwith controlled or dependent
sources.