1. Sri Eshwar College of Engineering,
Circuit Theory
Special Lecture by
Dr. N.Shanmugasundaram,
HOD - ECE Department,
Sri Eshwar College of Engineering,
Coimbatore.

2. Overview of the Presentation
Fundamental Electrical Parameters
Current & Voltage division rule, KVL & KCL
Resistors, Capacitance & Inductances
Mesh & Node Analysis
Network Theorems
Resonance (Series & Parallel)
Dr.NSS / SECE
April 7, 2019

3. Fundamental Electrical Parameters
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April 7, 2019

4. Fundamental Electrical Parameters
Measuring Unit
Symbol
Description
Charge
Coulomb Q
Q = C × V
Voltage
Volt
V or E
V = I × R
Current
Ampere
I or i
I = V ÷ R
Power
Watts W
P = VI  or  I2R
Resistance
Ohm
R or Ω
R = V ÷ I (DC)
Conductance
Siemen
G or ℧
G = 1 / R
Capacitance
Farad C
Q = CV, VC = 1/C  i dt
Inductance
Henry
L or H
VL = L(di/dt)
Impedance Z
Z2 = R2 + X2 (AC)
Frequency
Hertz Hz
ƒ = 1 /  T
Dr.NSS / SECE
April 7, 2019

5. Fundamental Electrical Parameters
Multiples and Sub-multiples
Prefix
Symbol
Multiplier
Power of Ten
Terra T
1,000,000,000,000
1012
Giga G
1,000,000,000
109
Mega M
1,000,000
106
kilo k
1,000
103 - 1
100
centi c
1/100
10-2
milli m
1/1,000
10-3
micro
1/1,000,000
10-6
nano n
1/1,000,000,000
10-9
pico p
1/1,000,000,000,000
10-12
Dr.NSS / SECE
April 7, 2019

6. Fundamental Electrical Parameters
i = i(t) = Im sin (ωt)
Passive elements cannot generate energy.
Common examples of passive elements are resistors, capacitors and inductors. Capacitors and Inductors can store energy but cannot generate energy.
Active elements can generate energy.
Common examples of active elements are power supplies, batteries, operational amplifiers.
Dr.NSS / SECE
April 7, 2019

7. Fundamental Electrical Parameters
By Ohm’s law:
The amount of Current (I) flowing through the Resistor R, is directly proportional to the Voltage (V) applied across it. (V = I x R)
Limitations:
Ohm’s law is not applicable in unilateral networks. Such types of network consist elements like a diode, transistor, etc.
It is not applicable for the non-linear network. (L, C)
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April 7, 2019

8. Fundamental Electrical Parameters
Peak Value, Average Value and RMS Value
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9. KVL & KCL Voltage & Current Division Rule
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10. Kirchoff’s Voltage & Current Law
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11. Voltage Division Rule
(VR2 = I x R2)
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12. Voltage Division Rule
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13. Current Division Rule
𝑰 𝟏 = 𝑰 𝑻 𝑹 𝟐 𝑹 𝑻
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14. Resistance, Capacitance and Inductors
Series and Parallel
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15. Series and Parallel Resistors
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16. SERIES AND PARALLEL RESISTORS
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17. Find Vx?
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18. Fundamental Electrical Parameters
Find i and i8 ?
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19. Capacitance in Series and Parallel
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20. Inductance in Series and Parallel
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21. Exercise Problems
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22. Mesh analysis is used to determine branch current in a given circuit.
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23. Dr.NSS / SECE
April 7, 2019

24. Network Theorems
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25. NETWORK THEOREMS
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26. NETWORK THEOREMS
Thevenin’s Theorem
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27. Max Power Transfer Theorem:
happens when
Rth = RL
Find the value of RL so that Max power transfers from Source to Load in above circuit?
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April 7, 2019

28. Superposition Theorem
Find I3 using
Superposition Theorem ?
I3 = I3’ + I3’’
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April 7, 2019

29. Series and Parallel
Resonance
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30. Series Resonance
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31. Parallel Resonance
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32. Thank you For your patience… Dr. N.Shanmugasundaram,
For Queries & Clarifications, Contact
Dr. N.Shanmugasundaram,
Prof & Head - ECE Department,
Sri Eshwar College of Engineering,
Coimbatore.
Dr.NSS / SECE
April 7, 2019