Summary Notes of Electrical Technology

ANSWER (Continue)

Q7 : Calculate the current flow through the 20 Ω resistor, R5 = RL for the circuit above by using Thevenin Theorem and
Norton Theorem.

ANS : Thevenin Theorem

Step 3 : Insert the load resistive load into the Thevenin’s Equivalent Circuit.
Calculate the current (IL) that flows through the 5 Ω resistor.

=
+

.
= +

= .

Did you know,
Thevenin-Norton
Equivalencies for this

question ?

136

ANSWER

Q7 : Calculate the current flow through the 20 Ω resistor, R5 = RL for the circuit above by using Thevenin Theorem and
Norton Theorem.

ANS : Norton Theorem
Step 1 : Remove the load resistance, RL and shorted the
A - B terminals to determine the Norton current, IN
using CDR,

= 4 3 + 1 + 2
= 4 + 3
= ,
30 60
30 + 60 + 50 + 10 = + X - CDR

= Ω
= + .

= =
= .

= . mA =

137

ANSWER (Continue)

Q7 : Calculate the current flow through the 20 Ω resistor, R5 = RL for the circuit above by using Thevenin Theorem and
Norton Theorem.

ANS : Norton Theorem Step 3 : Draw Norton’s Equivalent Circuit and
insert back the load resistor at terminal A – B.
Step 2 : Remove the load resistance, RL and open
current source. Calculate the open circuit
resistance at terminal A - B.

= 1 + 2 3 + 4 = ×
1 + 2 + 3 +
60
50 + 10 60 = 60 + 20 × 125
= 50 + 10 + 60 + 30
= .

= 30 + 30 = Ω 138

ANSWER

Q8 : By using Kirchoff’s Law, calculate each current I1, I2, I3 and VR1 VR3
voltage drop of R2 and power absorbed by the resistor.
ANS :
Loop 1:

෍ = ෍ Loop 1 VR2 Loop 2

= + (I1) (I2)

= + ( + ) Step 2 : Using Cramer’s rule, solve the unknown currents of simultaneous equations

= + + V
= + +
=
= + - - - - eqn 1

Loop 2: ∆= , = =ሼ − ( )} =

෍ = ෍
∆ = , = = ሼ − ( )} = ∴ = ∆ = = .
= + ∆

∆ = , = = ሼ − ( )} = − ∴ = ∆ = − = − .
∆

= + ( + ) Current flow through the R2 resistor is;
= + +

= + + = + = . + . = .

= + - - - - eqn 2

139

ANSWER (Continue)

Q8 : By using Kirchoff’s Law, calculate each current I1, I2, I3 and VR1 VR3
voltage drop of R2 and power absorbed by the resistor.
Loop 1 VR2 Loop 2
ANS :
(I1) (I2)
Voltage drop of R2,

2 = 2 2
= 113.34 50 = .

Power absorbed of R2,

= 2
= 113.34 2 50 = .

140

Reference

141

REFERENCE

Bakshi, U. A., & Bakshi, A. V. (2009). Circuit Theory. Technical Publications.
Bakshi, A. B. U. (2008). Circuit Analysis. Technical Publications.
CO, S., CO, M., CO, S., CO, S., & CO, S. U18ESEE101 BASIC ELECTRICAL & ELECTRONICS ENGINEERING. CURRICULUM AND
SYLLABUS (R2018) CHOICE BASED FLEXIBLE CREDIT SYSTEM, 37.
ESE, L. Babu Banarasi Das University, Lucknow.
Erickson, W. H., & Bryant, N. H. (1952). Electrical Engineering, Theory and Practice. Wiley.
Hiley, J., Brown, K. E., & Hughes, E. (2001). Hughes Electrical & Electronic Technology-either edition.
Hughes, E., Hiley, J., Smith, I. M., & Brown, K. (2005). Hughes electrical and electronic technology. Pearson education.
Mehta, V. K., & Mehta, R. (2012). Basic Electrical Engineering. S Chand.
Othman. A., Abdul Hamid. Z., Suradi. J. (2017). Electrical Technology. Selangor: Oxford Fajar.
Robertson, C. R. (2008). Fundamental electrical and electronic principles. Routledge.

142

Education : AUTHOR
❑ Master Science of Electronic System Design
ZURAIDA BINTI KAMARUDDIN
Engineering
❑ Bachelor in Electrical Engineering (Communication)
❑ Diploma in Electronic Engineering
❑ Diploma in Education (Electrical Engineering)

Teaching experience :
❑ Head of Electronic Engineering Program

(Computer) 4 years
❑ Teaching Electrical Technology > 5 years
❑ Lecturer in Electrical Engineering Department of

Sultan Idris Shah Polytechnic

Publication / Digest :
❑ Application of 38 Sensor in Arduino
❑ Digest 2017 : Pembangunan Strategi ZK

Berdasarkan Hubungan Masukan Dan Keluaran

143

Education : AUTHOR

❑ Master of Education ROBIAH BINTI UDIN
❑ Bachelor of Engineering (Electrical & Electronic)

Teaching experience :

❑ Teaching Electrical Technology > 10 years
❑ Lecturer in Electrical Engineering Department of

Sultan Idris Shah Polytechnic

144

AUTHOR

Education :
❑ Bachelor in Electrical Engineering (Electric)
❑ Diploma in Electrical Engineering with Education

Teaching experience :
❑ Working experience > 20 years
❑ Lecturer in Electrical Engineering Department of

Sultan Idris Shah Polytechnic

SUHARDI BIN CHE AHMAD

145



The following are some of the primary qualities

- Presenting electrical technology subjects in a straightforward
and understandable manner helps students apply ideas via the
use of examples

- Short summaries of each chapter are provided for students'
ease of reference