Experiment no.3
BEE Lab Manual
Title: To verify Kirchhoff’s Current law & Kirchhoff’s Voltage law in D.C. circuits.
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Estimated time to complete this experiment: 2 Hours
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Objective: To Understand distribution of Voltage & Current in a closed Electrical circuit.
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PEO to be achieved:
E2. To develop the Data Synthesis and Analysis capabilities in the student that assist in technical
concept formation and electronic product design.
E6. To impart proficiency in using hardware and software tools in order to deduce results, analyze,
design and develop engineering solutions.
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Expected Outcome of Experiment:
Ea. Graduates are expected to demonstrate knowledge of Applied Mathematics, Applied sciences,
Engineering Drawing and core Electronics Engineering
Eb. Graduates are expected to have the ability to Identify, Formulate and solve Electronics engineering
problems and design electronic circuits.
Ef. Graduates are expected to have skills, to use electronic equipment, modern engineering tools and
software in analysis, design and development.
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Books/ Journals/ Websites referred:
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B.L.Theraja “Electrical Engineering”
S.N.Singh, “Basic Electrical Engineering” PHI , 2011
http://www.electronics-tutorials.ws/dccircuits/dcp_4.html
http://www.allaboutcircuits.com/vol_1/chpt_6/4.html
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Pre Lab/ Prior Concepts: Operating Digital multimeter, Ohm’s law, Bread board connections.
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Historical Profile:
Kirchhoff's circuit laws are two equalities that deal with the conservation of charge and energy in
electrical circuits, and were first described in 1845 by Gustav Kirchhoff. Widely used in electrical
engineering, they are also called Kirchhoff's rules or simply Kirchhoff's laws.
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New Concepts to be learned:
Determination of current through a branch and voltage across a resistor in a given circuit.
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Experiment no.3
BEE Lab Manual
Requirements/ Equipment: D.C. Ammeter (0 – 10mA), D.C. Voltmeter (0 – 10V), Bread board,
connecting wires, Dual DC regulated power supply, Resistors as follows:
Sr. no Resistor
Value
1.
R1
200 Ohms, ½ W
2.
R2
100 Ohms, ½ W
3.
R3
390 Ohms, ½ W
4.
R4
100 Ohms, ½ W
5.
R5
820 Ohms, ½ W
6.
R6
1K Ohms, ½ W
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Explanation/ Stepwise-Procedure:
Kirchhoff’s Voltage law
It states that the algebraic sum of the products of current and resistances in each of the conductors in
any closed path in a network plus the algebraic sum of the e.m.fs. in that path is zero.
Ʃ IR + Ʃ e.m.f. = 0
Kirchhoff’s current law
It states that in any electrical network, the algebraic sum of currents meeting at a point (or junction) is
zero.
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Stepwise-Procedure
For KVL
1. Make the connections as per the circuit diagram.
2. Switch ON both the D.C. Sources.
3. Note down the values of VR1, VR2, VR3, VR4, VR5.
4. Switch OFF the D.C. supply.
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Experiment no.3
BEE Lab Manual
For KCL
1. Make the connections as per the circuit diagram.
2. Switch ON the D.C. Sources.
3. Note down the branch currents IR1, IR2, IR3 and ITotal
4. Switch OFF the D.C. supply.
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Circuit Diagram:
For KVL:
For KCL:
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Observations:
For KVL:
Sr. no.
Resistor
1.
R1
2.
R2
3.
R3
4.
R4
5.
R5
Calculated Voltage
(Volts)
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Measured Voltage
(Volts)
Experiment no.3
BEE Lab Manual
For KCL:
IR1
(mA)
IR2
(mA)
IR3
(mA)
I Total
(mA)
Verification of KCL
(Yes / No)
Measured
Calculated
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Calculations:
For KVL:
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Experiment no.3
BEE Lab Manual
For KCL:
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Conclusion: _______________________________________________________________________
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Experiment no.3
BEE Lab Manual
Real Life Application:
1. One can relate this experiment with distribution of currents for various rooms in a house where
all the electrical loads are connected in parallel.
2. A matrix version of Kirchhoff's current law is the basis of most circuit simulation software, such
as SPICE.
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Post Lab Questions:
1. Ten lamps are connected in parallel across a 12 V supply. What is the voltage across each lamp?
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2. Ten lamps are connected in series across a power supply. The voltage across each lamp is 6.0 V.
What is the voltage of the supply?
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3. State Kirchhoff’s laws of voltage and current.
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4. What are the limitations of KVL?
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5. What are the limitations of KCL?
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