FR. CONCEICAO RODRIGUES COLLEGE OF ENGINEERING
Department of Electronics Engineering
2. THEVENIN’S THEOREM
1.
Course, Subject & Experiment Details
Academic Year
Course &
Semester
Chapter No.
2014 – 2015
F.E. (ALL) – Sem. I
1
Hardware
Experiment Type Performance
2.
Estimated
Time
Experiment No. 2 – 02 Hours
Basic Electrical and Electronics
Subject Name Engineering Laboratory
Chapter Title DC Circuit
Subject Code
FEC105
Aim & Objective of Experiment
To verify Thevenin’s theorem in DC Circuit.
3.
Expected Outcome of Experiment
This experiment helps students in understanding the basic principle behind Thevenin’s theorem and
its applications in Network Analysis.
4.
Brief Theoretical Description
Thevenin’s Theorem states,
“Any linear, bilateral, two terminal network can be replaced with an equivalent voltage source (V th) in
series with an equivalent resistance (Rth).” The equivalent voltage source (Vth), which is known
as “Thevenin’s equivalent voltage”, is the open circuit voltage across the two terminals and the
equivalent resistance (Rth) is the effective resistance appearing across the terminals when all
sources are replaced by their respective internal resistance.
Basic Electrical and Electronics Laboratory- Experiment 2
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FR. CONCEICAO RODRIGUES COLLEGE OF ENGINEERING
Department of Electronics Engineering
The theorem can be experimentally verified by measuring the current through load resistance (at least
three different values) in the given circuit and then the current through the same load resistance in the
Thevenin’s circuit. Same value of currents observed through particular load resistance in both the
circuits proves the equivalence of the two circuits.
5.
Circuit Diagram & Experimental Setup
100Ω
100Ω
RTH
RL
10 V
RL
Vth
100Ω
+
_
+
_
IL
fig.2
fig.3
Fig 1
6.
IL
Fig 2
Apparatus and components required
1.
Breadboard
2.
Power supply
3.
Multimeter
4.
Connecting wires.
5.
0 - 10 V DC
1 No.
Resistances
Basic Electrical and Electronics Laboratory- Experiment 2
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FR. CONCEICAO RODRIGUES COLLEGE OF ENGINEERING
Department of Electronics Engineering
7.
Experimental Procedure
1.
2.
3.
4.
Connect the circuit as shown in fig.1.
For different values of RL, note the current through it.
Remove RL and note voltage across the two terminals (Vth)
Replace the voltage source by a short circuit and measure the resistance between the
terminals. (Rth)
5. Connect a voltage source of value Vth in series with a resistance Rth (TEC)
6. Connect the load resistance across the circuit and for different values of RL, note the
current through it.
7. Verify with the actual values.
8. 88
Observation Table
Thevenin’s Equivalent voltage (Vth)
=
Thevenin’s Equivalent resistance (Rth)
=
Load Current
Load
Resistance RL (Ω)
Actual Circuit
IL (mA)
Thevenin’s
Equivalent
IL (mA)
Theoretical
ckt.
IL (mA)
100
150
220
Basic Electrical and Electronics Laboratory- Experiment 2
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FR. CONCEICAO RODRIGUES COLLEGE OF ENGINEERING
Department of Electronics Engineering
9.
Conclusions & Inferences
.
10.
Post Lab Questions
1. Calculate the current in load resistance for the above circuit by applying Thevenin’s theorem.
2. Explain Max power transfer Theorem. In the above circuit find the max power that can be transferred
to the load resistance.
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Basic Electrical and Electronics Laboratory- Experiment 2
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