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A virtual interactive electromagnetic laboratory:an effective
pedagogical approach
Prof. S. V. KulkarniDepartment of Electrical EngineeringIndian
Institute of Technology Bombay, INDIA [email protected]
Forum for Electromagnetic Research Methods and Application
Technologies (FERMAT)
Presented at IEEE-INAE Symposium on Electromagnetic Education
and Research
SSN College of Engineering, Tamil Nadu, IndiaDecember 12-13,
2016
mailto:[email protected]
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Copyright
©The use of this work is restricted solely foracademic purposes.
The author of this work ownsthe copyright and no reproduction in
any form ispermitted without written permission by the author.
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Abstract
Electromagnetic Fields is one of the foundation courses in both
Electrical and Electronics EngineeringCurricula. It is generally
perceived to be a difficult-to-understand subject by the students.
If theconceptual understanding is not clearly assimilated by them,
the course gets shrouded in abstractnessand mathematical formulae.
It is essential to explain the involved theory through visuals and
real-lifepractical examples. By means of this virtual laboratory,
theories in electrostatics, magnetostatics, andtime-varying fields
are explained using graphical results obtained through MATLAB based
codes aswell as field distributions plotted using Finite Element
Method and Method of Moment basedcomputations.
This virtual laboratory has been designed by using Java Applets
which can provide interactive featuressuch as radio buttons and
provision for drawing contours. These applets have been launched
into webby using HTML pages and class files of the applets. A
Google form based interactive portal has alsobeen launched that
helps users to interact with developers directly. Users can access
the developedexperiments at the following link:
https://www.ee.iitb.ac.in/course/~vel/
Keywords—Electromagnetic field theory; Java Applets; Virtual
labs; Finite Element Method; Methodof Moment
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https://www.ee.iitb.ac.in/course/%7Evel/
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Biography
Dr. S. V. Kulkarni is Professor in the Department of Electrical
Engineering, Indian Institute of Technology Bombay,India.
Previously, he worked at Crompton Greaves Limited (1990-2001) and
specialized in the design anddevelopment of transformers up to 400
kV class. He was a recipient of the Young Engineer Award conferred
by theIndian National Academy of Engineering in 2000 for his
contributions to Electromagnetic Field Computations andHigh Voltage
Insulation Design in transformers. He was also honoured with the
Career Award for Young Teachersfrom All India Council for Technical
Education in 2001. He received Best Paper Awards in international
conferenceson transformers held in 2002 and 2006.He has authored a
book Transformer Engineering: Design, Technology, and Diagnostics,
Second Edition, publishedby CRC Press in September 2012. The first
edition published in 2004 received an overwhelming response
worldwide.He has also written a chapter Challenges and Strategies
in Transformer Design in the book Transformers: Analysis,Design,
and Measurement published by CRC Press in June 2012. He has also
adapted an undergraduate textbook onelectromagnetics for Asia,
Principles of Electromagnetics, Oxford University Press, published
in October 2015.His extensive interactions with transformer and
power industries are reflected in his numerous consultancy projects
forthem. He has organized several training programs on transformers
and computational electromagnetics for engineersfrom industries and
academia in India. He has also set up the Field Computation
Laboratory and the InsulationDiagnostics Laboratory in the
Electrical Engineering Department at IIT Bombay.He has more than
150 publications to his credit in reputed journals and conferences.
He has one US patent ontransformer deformation diagnostics. He is a
Fellow of the Indian National Academy of Engineering. He is also
anEditor of IEEE Transactions on Power Delivery. His current areas
of research include Analysis and Diagnostics ofPower Transformers,
Advanced Electromagnetic and Coupled Field Computations, and
Distributed Generation andSmart Grids.For more details, see:
http://www.ee.iitb.ac.in/wiki/faculty:svk
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http://www.ee.iitb.ac.in/wiki/faculty:svk
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Outline Issues and challenges in teaching electromagnetics
Important concepts that need to be elaborated
Ways of effective teaching
Web based virtual laboratory
Some sample experiments
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Issues and Challenges in Teaching Electromagnetics The course is
comparatively abstract as compared to circuits-
based courses
The subject should not be taught as a mathematical course
“Physics” and “What is happening in space” need to
beexplained
General feeling in academia: “Students find it difficult to
understand and pass the subject” “Teachers do not like to teach the
subject”
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Important Concepts that Need to be Elaborated Divergence and
Curl
Divergence of a vector (Gauss’s law in Maxwell’s equation)
Many students are not clear whether ρv is free charge density or
boundcharge density?
Curl of a vector (Ampere’s law in Maxwell’s equation)
Does the curl of the magnetic field produced by a current
carryingconductor remain same in the inner and outer regions of the
conductor?
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vρ∇ ⋅ =D
∇× =H J
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Continuity equation and displacement current density
How the above equation can be related to Kirchhoff's Current
Law,particularly to currents in a circuit consisting of R, L and C
elements?
εr and μr Understanding the two as complex numbers
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v
tρ∂
∇ ⋅ = −∂
J
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Coulomb's and Lorentz gauge Understanding that Coulomb's gauge
is a special case of Lorentz gauge
Electric length and transient time at high frequencies
Free space impedance – a pure resistance
Radiation at high frequencies: visualization
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Vt
µε ∂∇ ⋅ = −∂
A
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Ways of Effective Teaching Appropriate mix of theory and
practical examples involving
real life equipment and systems
Emphasis on “spatial distribution” of fields rather than
thegoverning math
Creating a common set of presentations
Inclusion of numerical techniques (FEM, MoM) into thecourse
Interactive web based teaching techniques
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Web Based Laboratory One of the main difficulties in learning
electromagnetics is
visualization of fields Field distributions in different
practical devices are governed
by partial differential equations, and it is very difficult to
solvethem analytically
Numerical techniques like Finite Element Method (FEM) andMethod
of Moments (MoM) can be used to solve thesegoverning differential
equations, but these are not easilyaccessible to or understood by
students
This web based lab uses FEM and MoM results to explainbasic
concepts
Applications have been built by using Java based applets,which
are deployed into web by using HTML
11Ref: https://www.ee.iitb.ac.in/course/~vel/
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Java applets Interactive features for the web based lab are
provided by Java applets,
which may not be provided by HTML alone. Features like check
boxes, buttons, and user actions with mouse can be
incorporated/captured Applets can change field plots in response
to the user selection This makes applets well suitable for
demonstration, visualization, and
teaching
To run these Java applet based experiments on a
personalcomputer, Java environment is needed to be configured
For this, the user needs to install the latest version of
JDK(Java Development Kit), and JRE (Java Runtimeenvironment): open
source software
After installing these software, security issues have to
becleared by adding the website link to the exception site list
inthe Java control panel
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Main Features of the Web Based Lab Experiments in the lab are
designed using FEM/MoM and
Matlab based analytical results of familiar practical
applications Users can change the parameters assigned in each
experiment
and can visualize how the fields depend on these parameters A
google form based interactive portal has been launched so that
users can directly give feedback to the developers It is very
easy to create Java environment in a personal
computer: open source software and one time installation
Experiments have been chosen in accordance with
undergraduate curricula
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Electron Movement in Different Media
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Electron moving in a dielectric
Electron moving in a metal
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Eddy Currents and Skin Effect
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Flux penetration
Variation of field
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Direction of Fields in a Rectangular Waveguide
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Antenna Radiation
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Current distribution Radiation field
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References
Matthew N.O. Sadiku and S.V. Kulkarni, Principles of
Electromagnetics. Sixth Edition, AsianAdaptation, New Delhi, Oxford
University Press, India, September, 2015, 908 pages,
(Asianadaptation of the original text book: Matthew N.O. Sadiku,
Elements of Electromagnetics, SixthInternational Edition, Oxford
University Press)
M. F. Iskander, “Technology-based electromagnetic education,”
IEEE Transactions on Education,Vol. 50, No. 3, pp. 1015-1020, Mar.
2002.
K. Preis, I. Bardi, O. Biro, R. Hoschek, M. Mayr, and I. Ticar,
“A virtual electromagnetic laboratoryfor the classroom and the
WWW,” IEEE Transactions on Mangetics, Vol. 33, No. 2, pp.
1990-1993, Mar.1997.
M. Munoz, “Using graphical based software to aid in the
understanding of electromagnetic fieldtheory,” in Froniters in
Education Conference , Vol. 2, pp. 863-867, Aug. 1996.
V. Pulijala, A. R. Akula, and A. Syed, “A web-based virtual
laboratory for electromagnetic theory,”in Fifth International
Conference on Technology for Education, pp. 13-18, 2013.
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Thank you
A virtual interactive electromagnetic laboratory:�an effective
pedagogical approach��CopyrightAbstractBiographyOutlineIssues and
Challenges in Teaching Electromagnetics�Important Concepts that
Need to be Elaborated�Slide Number 8Slide Number 9Ways of Effective
TeachingWeb Based LaboratorySlide Number 12Main Features of the Web
Based LabCurl of a VectorElectron Movement in Different MediaEddy
Currents and Skin EffectDirection of Fields in a Rectangular
WaveguideAntenna Radiation References�Slide Number 20