CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > General Forums > Electromagnetics

Motivation to study electromagnetics?

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 2, 2019, 19:18
Default Motivation to study electromagnetics?
  #1
New Member
 
Navarun Jagatpal
Join Date: Feb 2019
Posts: 1
Rep Power: 0
navarunj is on a distinguished road
I'm a graduate student, working on a PhD-ECE. I'm very interested in photonics, especially building practical real-world photonic devices. However, at my university, grad students have to study photonics and electromagnetics together. Therefore, I had to take a course last semester called Advanced Engineering Electromagnetics. The course used a textbook of the same name, written by Constantine Balanis, and I suspect that some people on this forum might be familiar with this book.

I didn't do well in the course. This was partly because I was extremely unmotivated. However, I do have to learn the concepts in the course, because I'm taking the qualifying exam in June. I'm hoping that people on this forum can help me with motivation.

My main question is, why should I care? I signed up for a degree in engineering. But then, this class didn't feel like an engineering class at all. It felt like it was just a lot of math and theoretical physics.

To me, engineering means building things. It means that a person asks me "Hey, can you to build a device that does XYZ?" And then I plan it out, I design the device, possibly using mathematical models as part of the design process. And then I buy the parts, and put them together, and I build the device. And then I give the device to the other person, and they can use it.

But it seems like this class and this textbook don't contain anything like that. They consist entirely of theory and theoretical problems. My professor himself described them as "toy problems." Why should I care about toy problems?

I want to ask everyone in this forum specifically about magnetic vector potential. It's something that came up repeatedly throughout the course, but I still don't understand why it's so important. First of all, what is it? Obviously it's a vector field, but what is it, physically? I've seen that it's defined by the equation:

\vec{B} =  \nabla \times \vec{A}

But, so what? That equation doesn't really tell me what it is, or why I should care about it. Can you touch it? Can you see it? Can you measure it? I know that \vec{B} can be measured, using a Hall Effect Sensor. But it seems that there is no way to measure \vec{A}.

Second of all, can you actually use \vec{A} to help build and design a device? It would be nice if someone could give me a specific real-world example, in which a customer says to an engineer "I want you to build a device that does XYZ." And then the engineer designs the device, and, as part of the design process, he writes down equations containing magnetic vector potential, and then he uses those equations to help him optimize and improve the device. Can anyone give me an example like that? (I guess the device would be an antenna, in this case? I honestly don't know. I'm completely lost here.)

This post really just scratches the surface of things that I didn't like about this course/textbook. There are many many other reasons why I was unmotivated, and frustrated, and confused, and I might start new threads in the future with my additional questions about this.
navarunj is offline   Reply With Quote

Old   March 9, 2019, 09:00
Default
  #2
Senior Member
 
Join Date: Oct 2013
Posts: 393
Rep Power: 13
chriss85 will become famous soon enough
I don't think i can help you out regarding your frustration. You seem to be a very practially oriented person. Understanding electromagnetics requires quite some theory which you may have to fight with.


Regarding the vector potential, it is useful because magnetic fields are formed as rotational fields around electrical and displacement currents. This means they will have a somewhat complex physical shape that may be difficulto to understand/investigate when it comes to real world geometries. If you use the vector potential you will see a field distribution which might be easiert to relate to the current distribution.


Apart from that, the magnetic vector potential is often used to solve magnetic field distributions, be it in analytical form or with numerical methods.


Regarding the physical meaning, I think there are some experiments in quantum mechanics that imply that the magnetic vector potential can be viewed as the true underlying phenomenon rather than the magnetic field but I don't remember this so clearly. I don't know of any more common cases which cannot principially be explained with the B-field as well. But you will have a harder time in some cases
chriss85 is offline   Reply With Quote

Old   April 22, 2019, 07:16
Default
  #3
New Member
 
MayraHe's Avatar
 
MayraHowle
Join Date: Apr 2019
Location: Buffalo Grove, IL
Posts: 1
Rep Power: 0
MayraHe is on a distinguished road
Quote:
Originally Posted by navarunj View Post
I'm a graduate student, working on a PhD-ECE. I'm very interested in photonics, especially building practical real-world photonic devices. However, at my university, grad students have to study photonics and electromagnetics together. Therefore, I had to take a course last semester called Advanced Engineering Electromagnetics. The course used a textbook of the same name, written by Constantine Balanis, and I suspect that some people on this forum might be familiar with this book.

I didn't do well in the course. This was partly because I was extremely unmotivated. However, I do have to learn the concepts in the course, because I'm taking the qualifying exam in June. I'm hoping that people on this forum can help me with motivation.

My main question is, why should I care? I signed up for a degree in engineering. But then, this class didn't feel like an engineering class at all. It felt like it was just a lot of math and theoretical physics.

To me, engineering means building things. It means that a person asks me "Hey, can you to build a device that does XYZ?" And then I plan it out, I design the device, possibly using mathematical models as part of the design process. And then I buy the parts, and put them together, and I build the device. And then I give the device to the other person, and they can use it.

But it seems like this class and this textbook don't contain anything like that. They consist entirely of theory and theoretical problems. My professor himself described them as "toy problems." Why should I care about toy problems?

I want to ask everyone in this forum specifically about magnetic vector potential. It's something that came up repeatedly throughout the course, but I still don't understand why it's so important. First of all, what is it? Obviously it's a vector field, but what is it, physically? I've seen that it's defined by the equation:

\vec{B} =  \nabla \times \vec{A}

But, so what? That equation doesn't really tell me what it is, or why I should care about it. Can you touch it? Can you see it? Can you measure it? I know that \vec{B} can be measured, using a Hall Effect Sensor. But it seems that there is no way to measure \vec{A}.

Second of all, can you actually use \vec{A} to help build and design a device? It would be nice if someone could give me a specific real-world example, in which a customer says to an engineer "I want you to build a device that does XYZ." And then the engineer designs the device, and, as part of the design process, he writes down equations containing magnetic vector potential, and then he uses those equations to help him optimize and improve the device. Can anyone give me an example like that? (I guess the device would be an antenna, in this case? I honestly don't know. I'm completely lost here.)

This post really just scratches the surface of things that I didn't like about this course/textbook. There are many many other reasons why I was unmotivated, and frustrated, and confused, and I might start new threads in the future with my additional questions about this.
I was touched by this post, probably because I had the same situation two years ago.
Today it is easy for me to talk and write about it, but two years ago I was ready to leave the University. And the course was quantum chemistry with many mathematical formulas, integrals. Students classmates asked me that I have something with brains because this is just an ordinary subject of many. Learn it, like all other subjects. The teachers did not understand me, because my term paper on chemistry was the best.
But I then went to chemistry, where there are solids, solutions, reactions, discoloration, heat release. All these properties and qualities, they can be seen, measured and even touch. I passed mathematics, physics with similar formulas, integrals and differentials and this didn’t bother me very much. But the subject of quantum chemistry, I could not accept as a subject.
There were questions: why this is needed, there is no practice. It was the art of the possible. Here everything reminded me of politics but did not like politics and deceitful politicians (there were such people in our city).
At first, I had thoughts about translating to chemistry with a pedagogical bias (colleges). And then I decided to quit university altogether.
My boyfriend helped me rectify the situation (he is also a chemical student, but one year older), he suggested that I make a deal: I order a written work in an online service, and he will work with me and help me to learn the tricks of passing the exam, rather than learning. He proposed the parameters of the written work and I ordered the course written work in the next online service (there are a lot of them). After that, he started working with me when we met.
When the work came, it turned out that it was dedicated to fully practical applications of quantum chemistry, although it was a bit popular. I learned that new medicinal substances are already synthesized on the basis of the tasks of quantum chemistry. In quantum chemistry, artificial intelligence, which helps to select substances and materials with predetermined properties, is already working successfully. It is not difficult to measure (nuclear magnetic resonance, electron magnetic resonance, proton magnetic resonance, infrared spectroscopy, Mössbauer spectroscopy). Although the interpretation was rather speculative and uncertain, these methods turned out to allow quite reliably to solve the classical problems of chemistry to determine the quantitative and qualitative composition of a substance at the molecular level. And if earlier chemistry was substances, solutions, and reactions, then modern chemistry can no longer do without the use of quantum chemistry or its applications.
It turned out that there is even a separate subdivision of quantum chemistry - computational chemistry. You can still describe my insights for a long time, but the result was! I passed the exam, although the work was too popular and the professor identified it as weak.
And my surprise was great that after the exam I read almost all of this information from my work on elementary Wikipedia and many popular sites on quantum and computational chemistry. But I could do this and not order a written work in the online service.
I made conclusions: - never order written works, and especially at foxiesessay.com;
- firstly - if there are problems in the study of the subject - it is necessary to consider it from several sides,
- secondly, mental fatigue and physiological fatigue (spring, vitamins, lack of sun and good impressions);
- thirdly - share your problem with friends (it is important not only to share but also take their clues to heart);
- fourth, never stumble on a private matter that could ruin your education and ruin your career (how many young people could not go to the University didn’t have the right qualities);
- in the fifth - always double-check your thoughts and important actions with the help of Google (it has enough tips).
That's all my thoughts. Good luck to you Navarun Jagatpal!
__________________
ab initio nullum, semper nullum
MayraHe is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Real results from a simple study WHAT am I doing wrong? jon g FloEFD, FloWorks & FloTHERM 5 November 14, 2018 09:46
[ICEM] Mesh Independence study Carlos Modesto ANSYS Meshing & Geometry 4 July 7, 2017 06:57
[ICEM] (New to CFD) How to do a mesh refinement study w/ Fluent? JAviles ANSYS Meshing & Geometry 1 June 25, 2014 12:09
grid study, important question hamid1 FLUENT 1 August 4, 2013 00:14
[ANSYS Meshing] grid study, important questions hamid1 ANSYS Meshing & Geometry 2 February 10, 2012 13:28


All times are GMT -4. The time now is 02:50.