STUDY AND
VERIFICATION OF
KIRCHOFF’S CURRENT
LAW
A PROJECT REPORT
Submitted by
AFRAH NAJEEB
In partial fulfilment for the award
Of
ALL INDIA SENIOR CERTIFICATE EXAMINATION
In
PHYSCIS
SANA MODEL SCHOOL,CHENNAI - 600 056
CENTRAL BOARD OF SECONDARY EDUCATION
2022-2023
SANA MODEL SCHOOL,CHENNAI 600 056
BONAFIDE CERTIFICATE
Certified that this project report“…………………………………………….”
Is the bonafide work of “……………………………..………………………”
Of grade ….…………….…., Register Number ……………….………….
Who carried out the project work under my(our) guidance and
supervision at Sana Model School, Chennai.
SIGNATURE
SIGNATURE
PHYSICS TEACHER
PRINCIPAL
Sana Model School, Chennai
Sana Model School,Chennai
Submitted for the physics practical examination held on ____________________
INTERNAL EXAMINER
EXTERNAL EXAMINER
ACKNOWLEDGEMENT
With immense pleasure. I would like to thank those who have
helped me in completing this project work.
I extremely thank the almighty who guided me in completion of
the project and who is always there to help me.
I am thankful to my parents for their extreme and unlimited
support for me to work with the project.
I thank my principal Mrs. NAJIA TAHMEEN for her
immense encouragement , providing us with all facilities and all
kind of moral support to carry out this project work.
I take this opportunity to give my special thanks to my physics teacher
Mr. AJAS AHMED for his inevitable help. It is much
of their guidance that endeavours to complete this project.
I also thank the whole staff of physics department for their timely help.
I would like to thank my friends who have helped me with their
Suggestion for the completion of this project.
CONTENTS
S.NO
CONTENT
Pg.NO
1
Abstract
1
2
Introduction
2
3
Theory
3-4
4
Material required
5-6
5
Circuit diagram
7
6
Procedure
8
7
Analysis 1
9
8
Analysis 2
10
9
Analysis 3
11
10
Analysis 4
12
11
Analysis 5
13
12
Analysis 6
14
13
Observation
15
14
Component Analysis
16
14
Result
17
15
Application
18
16
Bibliography
19
ABSTRACT
The purpose of this project is to verify “KIRCHOFF’S
CURRENT LAW” and it deals solely with current.
Kirchhoff’s Current Law is the most fundamental tool used in
the analysis of electric and electronic circuits. The objective of
applying this laws to a circuit is to determine the behavior of the
currents throughout the circuit. This handout will provide a
summary of law as well as examples of it’s application.
i
A circuit was built using the given schematic. This circuit was
J
also drawn in multisim. The circuit was then analysed using
three separate methods: The Kirchoff’s law ,multisim stimulatio
and a digital multi-meter
Kirchoff’s current law was found to be valid after comparing
l
n
.
.
The results from all three tests
INTRODUCTION
Many of the electrical circuits are complex in nature and the
j
computations required to find the unknown quantities in such
h
circuits, using simple ohm’s law and series/parallel combination
K
simplifying methods is not possible. Therefore, in order to simplify
h
these circuits Kirchhoff’s laws are used.
These laws are the fundamental analytical tools that are used to find
the solutions of voltages and currents in an electric circuit whether it
can be AC or DC. Elements in an electric circuit are connected in
numerous possible ways, thus to find the parameters in an electrical
circuit these laws are very helpful.
THEORY
Kirchoff’s Current Law
Kirchoff’s Current Law (KCL) deals with the currents flowing into and
out of a given node. KCL states that the sum of all currents at a node
must equal zero. This is illustrated in Figure 2.
Figure 2: An example of KCL
The equation obtained by KCL for the node shown in Fig. 2 is
I1 −I2 −I3 =0. (2)
In the case of KCL the passive sign convention deals with the direction
of currents with respect to the node. Currents entering the node must
have opposite signs as those exiting the node.
♦
Sum of all currents entering a node is zero.
♦ Sum of currents entering the node is equal to
sum of currents leaving the node.
Before going to know more about Kirchhoff’s current law, we have to
consider some of the terms related to electric circuits.
Node: Node or junction is a point in the circuit where two or more
electrical elements are connected. This specifies a voltage level with a
reference node in a circuit.
Branch: The continuous conducting path between two junctions which
contains electrical element in a circuit is referred as branch.
MATERIALS REQUIRED
1. Battery Eliminator
A device powered by an
electrical source other than a
battery, which then converts
the source to a suitable DC
voltage that may be used in the
circuit
2. Decade Resistance Box
An instrument for measuring
and comparing electrical
resistances.
3. Voltmeter
An instrument for measuring
electrical potential in volts
4. Ammeter
An instrument for measuring
electric currents in amperes.
5. Connecting wires
CIRCUIT DIAGRAM
PROCEDURE
1. Connections are made as per the circuit diagram.
2. Switch on the DC power supply
3. Measure the current values using multi-meter
4. Note down the corresponding reading
5. Calculate the total current theoretically .
6. Verify the values using multisim stimulation .
7. Finally verify KCL .
8. Repeat the same procedure for different values of voltages.
ANALYSIS 1
Theoretical :
Simulation :
Practical :
ANALYSIS 2
Theoretical :
Simulation :
Practical :
ANALYSIS 3
Theoretical :
Simulation :
Practical :
ANALYSIS 5
Theoretical :
Simulation :
Practical :
ANALYSIS 6
Theoretical :
Simulation :
Practical :
OBSERVATION
Applied
Current through the ammeter
(mA)
Voltage
Theoretical Simulation Practical
(V)
%Erorr
Volts
0.667
0.667
0.66
0%
1.33
1.33
1.26
0.1%
2.00
2.00
1.98
0%
2.66
2.66
2.66
0%
3.33
3.33
3.33
0%
4.00
4.00
3.86
0.04%
2V
4V
6V
8V
10 V
12V
COMPONENT ANALYSIS
S.NO
COMPONENT
NUMBER
COST
(in Rs)
1
Battery Eliminator
1
543
2
RDB
3
3500
3
Ammeter
1
149
4
Voltmeter
1
175
5
Connecting wires
14
10
Total = 4377
RESULT
Using Kirchoff’s Current Laws the currents is theoretically
calculated & practically verified.
The simulation of the circuit verified KCL. This was shown by
multisim found the sum of the two currents exiting the node to be
equal to the current entering the node. The experimental results
of the KCL test were not so close. There was less than two
percent error between the measured and calculated I1’s. This
error is acceptable in stating that KCL is true.
APPLICATIONS
• By using these laws, we can find the unknown resistances,
voltages and currents (direction as well as value).
• In the branch method, finding the currents through each
branch carried by applying KCL at every junction .
• In the loop current method, finding current through each
independent loop is carried by applying KVL for each loop
and counting all the currents in any element of a circuit.
• Used in nodal method of finding voltages and currents.
• These laws can be applied to analyse any circuit regardless
of the composition and structure of it.
BIBLIOGRAPHY
https://www.electronicshub.org/kirchhoffs-laws/
https://webstor.srmist.edu.in/web_assets/srm_mainsite/files/
files/EC0122-labmanual.pdf
https://www2.gvsu.edu/peirsonb/kvl_kcl_ohms_law.pdf
https://godavaricoejal.ac.in/Admin/DOWNLOAD/27.pdf
https://www.multisim.com/create/
NCERT class 12 textbook
ANALYSIS 4
Theoretical :
Simulation :
Practical :