This document provides instructions for an experiment to verify Kirchhoff's Current Law (KCL) using a circuit connected to a breadboard. The experiment uses a regulated DC power supply, digital multimeter, resistors, and connecting wires to build the KCL circuit. Students are asked to take voltage and current readings at different points in the circuit and use KCL calculations to determine if the experiment's observations match the theory. The objectives are to introduce students to KCL, demonstrate a KCL circuit, and have students practice applying KCL calculations.

1. DISCOVER . LEARN . EMPOWER
INSTITUTE UIE
DEPARTMENT ACADEMIC UNIT-3
Bachelor of Engineering
Subject Name Basic Electrical & Electronics Engineering Lab
Subject Code 22ELH-101
Prepared By
Dr. Meenakshi
Experiment 1
Kirchhoff’s Current Law

2. Importance of Basic Electrical & Electronics
Engineering
• Use from home appliances to industrial plants.
• Usage in communication and satellite navigation system.
• Handles in electronics equipment and computers.
• Deals with the problem of power transmission and motor control.
• Control and monitor the medical appliances in hospitals.
• High voltage applications with heavy current.
• Robotics applications.
• Product designing and development.
2

3. 3
Course
Objectives
S. No. Objectives
1 To meet students with basic knowledge of dc circuits, electromagnetism and ac fundamentals.
2
To aware about introduction to single and three phase ac circuit with their construction and
working principles.
3
To provide knowledge about electrical safety measures and wiring system to protect from short
circuits.
4 To make familiar with various rotating electrical machines with their applications.
5 To give brief knowledge about transducers and operational amplifiers.
https://www.quora.com/What-are-the-differences-
between-a-circuit-and-an-electric-circuit

4. 4
Course
Outcomes
CO
Numbe
r
Title Level
CO1
Students will be able to establish the equations that characterize the
performance of an electric circuit as well as solving both single phase and
three-phase AC circuits in sinusoidal steady state.
Remember
CO2
Students will be made aware about the electrical safety and
implementation of electric wiring.
Understand
CO3
Introducing students to the areas of basic concepts of rotating electrical
machines with their applications, transducers and batteries.
Understand
CO4
Students will be able to comprehend interfacing of analog to digital and
digital to analog converter with the help of operational amplifier.
Understand
https://in.pinterest.com/pin/240661173823316
229/

5. Objective
• The objective of this Lab activity is to verify Kirchhoff's Current Law
(KCL) using mesh and nodal analysis of the given circuit.
5

6. Apparatus Required
6
S.No. Experiment Name Specification &
Rating
Quantities in No.
1. Regulated variable DC supply 0 – 30 V, 0 – 2 A 1
2. Digital multimeter 0 – 2 A 6
3. Resistor Of different values 6
4. Connecting wires As per requirement

7. Breadboard
• A breadboard is used to make
up temporary circuits for testing or to
try out an idea.
• A breadboard is a rectangular plastic
board with a bunch of tiny holes in it.
• No soldering is required so it is easy to
change connections and replace
components. Parts are not damaged
and can be re-used afterwards.
7
Fig.1 Breadboard
https://www.sciencebuddies.org/science-fair-
projects/references/how-to-use-a-breadboard

8. Breadboard
• A breadboard is basically consists of
two parts.
• Upper part is connected in vertically
mode.
• Lower part is connected in
horizontally mode.
8
Fig.2 Breadboard
https://learn.sparkfun.com/tutorials/how-to-use-a-
breadboard/all

9. Breadboard Trainer Kit
• A breadboard is a construction base
for prototyping of electronics.
• In the 1970s the solderless
breadboard (plugboard, a terminal
array board) became available and
nowadays the term "breadboard" is
commonly used to refer to these.
9
Fig.3 Breadboard trainer kit
http://www.maxwellindia.com/digital_&analog
_breadboard_trainer.php

10. Multimeter
• A multimeter is mainly used to
measure the three basic electrical
characteristics of voltage, current and
resistance.
• It can also be used to test continuity
between two points in an electrical
circuit.
• The multimeter has multi
functionalities like it acts as ammeter,
voltmeter and ohmmeter.
10
Fig.4 Multimeter
https://electricalacademia.com/instrumentation-and-
measurements/digital-multimeter-working-
principle/attachment/drawing1-12/

11. Working of Digital Multimeter
• (i) Display: The LCD screen present on the upper portion of the
multimeter basically displays four or more digits and also shows
negative value if necessary.
• (ii) Selection switch: It allows the user to set the multimeter to read
different electrical parameters such as milliamps (mA) of current,
voltage, resistance, capacitance etc.
• (iii) Terminals: Two terminals are available on the front of every
multimeter except in some four ports are available for measuring
current in mA or A. We plugged two leads into these terminals which
are of different colors i.e. one is of red color and other is of black
color.
11

12. Working of Digital Multimeter
DMM Leads:
(i) Red lead
• Connected to voltage, resistance or ampere port.
• Considered as a +ve connection of a circuit
(ii) Black lead
• Connected to the common or ground port.
• Considered as a -ve connection of a circuit.
12

13. Resistance
• Resistance is a measure of the
opposition to current flow in an
electrical circuit. It is measured in
ohms.
• It is represented by the uppercase
letter R.
• When an electric current of
one ampere passes through a
component across which a potential
difference of one volt exists, then the
resistance of that component is one
ohm.
13
Fig.5 Resistance
https://www.electricalclassroom.com/elect
ric-resistance-what-is-resistance/

14. Colour Coding
14

15. Connecting Wire
• Connecting wires provide a medium
to an electrical current so that they
can travel from one point on a circuit
to another.
• In the case of computers, wires are
embedded into circuit boards to carry
pulses of electricity.
15
Fig.6 Connecting wires
https://www.schrack.com/shop/kvadra-70m-
connecting-wires-5x1-5mm2-li35000095.html

16. Theory
• It states that the algebraic sum of all the currents meeting at a
junction or a node in any electric circuit at any instant is zero.
ΣI = 0
• Algebraic sum means we have to consider the sign convention. If
current enters at node it will take as positive value and if current goes
away from node it will take negative value.
16

17. KCL Circuit
17
Fig.7 Circuit diagram of KCL

18. Observation Table
18
Sr. No.
Voltmeter
V (V)
Ammeter
I1 (A)
Ammeter
I2 (A)
1

19. Theory
• Kirchhoff’s laws are used to determine the current and voltage in different
branches of an electric circuit which may not be easily solved by Ohm’s law.
These laws are applicable to both AC and DC circuits.
• Statement of Kirchhoff’s First Law or Kirchhoff’s Current Law (KCL) or Point Law:
• It states that the algebraic sum of all the currents meeting at a junction or a
node in any electric circuit at any instant is zero.
• Explanation:
• Consider that few conductors are meeting at point M as in Fig. 1. The arrows
indicate the direction of current flow. The currents I2 and I4 are coming towards
the junction M and currents I1 and I3 are going away from the junction. Assume
positive sign for incoming currents and negative sign for outgoing currents.
19

20. KCL Circuit
20
Fig.1 KCL circuit

21. Calculation
• According to KCL,
Algebraic sum of incoming current = Algebraic sum of outgoing current
• i.e. I1= I2+ I4
• I2= I5+ I6
• I3= I6
21

22. Observation Table
22
Sr. No.
Supply Voltage
(Vdc) (V)
Ammeter
I1 (A)
Ammeter
I2 (A)
Ammeter
I36 (A)
Ammeter
I4 (A)
Ammeter
I5 (A)
1.
2.

23. Learning Outcomes
• On completion of the course students will be able to understand
• The measurement of Resistance, Voltage & Current.
• Designing of Series & Parallel Circuit.
• Test and Verify the KCL law.
23

24. Summary
Introduction to KCL circuit.
Demonstration of KCL circuit.
Calculation of KCL circuit.
24

25. References
Textbooks of Basic Electrical & Electronics Engineering:
Fundamentals of Electrical Circuits by Charles k.
Electrical Technology by Surinder Pal Bali, Pearson Publications.
Videos:
• https://www.youtube.com/watch?v=shFopYgNvoM
• https://www.youtube.com/watch?v=56fIDi-AwY4
25

26. THANK YOU
For queries
Email: meenakshi.e10466@cumail.in