Anyone who struggled to understand E&M at first, any tips?

[starstruck_]

hey!

It's me again.

For anyone who has been answering my questions // looking at my posts (thank you), you've probably already been aware that I never touched electricity in high school - the last time I did electricity and magnetism was in grade 11 and I couldn't solve a single circuit that year.

This second term of physics for me was brutal. I somehow ended up being able to solve circuits without much practice or trouble but when it came down to electric fields, gauss's law, maxwell's equations, faraday's law//lenz's law, and such, my brain just completely shut down. I understand the notes that we take in class, but I can't pick out the details I'm supposed to pick out like I used to be able to do for mechanics.

I failed the first test we did for the E&M part of the course (the class average was a 50% for that test though). The second one was supposed to be easy, I still barely passed.

I just CANNOT seem to wrap my head around E&M no matter how many videos I watch, or problems I do. I feel like there are gaps- in what is being explained to me so I don't have the entire picture or I'm just struggling to imagine these concepts to get the full picture.

Almost like grade 11 physics vs grade 12. Nothing made too much sense in grade 11 and then come grade 12 they went over the same concepts but gave a more detailed picture and suddenly everything made sense. I'm so frustrated with this, I wanted to do well this term and now 10% of my over-all grade is a 50 something.

Any tips? Extremely desperate to do well on my final for this term ://

 

[Arman777]

I just CANNOT seem to wrap my head around E&M no matter how many videos I watch, or problems I do. I feel like there are gaps- in what is being explained to me so I don't have the entire picture or I'm just struggling to imagine these concepts to get the full picture.

Find that gaps and focus on them. My best advice is open a textbook read carefully and try to do all (or most of the ) problems in each chapter. If you realize that there are parts that you still don't understand then you can ask your teacher or search online.

 

[scottdave]

Have you tried this: http://www.feynmanlectures.caltech.edu/

 

[Dishsoap]

E&M is tricky - it's not as intuitive as a ball rolling down a ramp. You said you are able to solve problems - what is the difference between these problems and the ones on the exam? Are they trickier? Are you given more superfluous information? Are the simplifications you can make different?

 

[Dr. Courtney]

Revisit the areas of weakness revealed by missed questions on the tests.

Re-read the relevant sections in the book, review the relevant sections of your notes, and rework all the homework problems on the same topics.

 

[starstruck_]

E&M is tricky - it's not as intuitive as a ball rolling down a ramp. You said you are able to solve problems - what is the difference between these problems and the ones on the exam? Are they trickier? Are you given more superfluous information? Are the simplifications you can make different?

It's hard for me to imagine the scenarios in E&M (I've been struggling with picturing and imagining things in a lot of my subjects this term but mostly physics)

The problems on our test were actually easier than the homework, but I ended up not being able to reason out the connections between different concepts or how the equations fit together and I missed 2 of the 4 questions on it. One of them was the exact same as a homework problem but I couldn't recall the concepts that were associated with it at all.

 

[marcusl]

A strong math background is key to E&M, especially calculus. A good understanding of Gauss’s law and Stokes‘s theorem from vector calculus, for example, directly set you up for mastering some tricky concepts in E&M. Evaluate your math prep all the way back (calculus, trig, algebra) and restudy or retake subjects as needed. Physics builds mercilessly on prior concepts, so weakness in a fundamental area can cascade.

 

[clope023]

You need to be able translate the equations to pictures of physical phenomena.

When you see a del operator operator you should see a point with arrows pointing away from it (or towards the point if it's negative)

When you see a curl you should a bunch of arrows revolving about some center (pointing the other way if it's negative).

When you see flux you should see a bunch of arrows hitting the top of a surface at some angle.

The book div,grad,curl might be good for getting a physical picture attached to the equations:

https://www.amazon.com/dp/0393925161/?tag=pfamazon01-20

I struggled with E&M before too but trying to translate the equations in the way I'm talking about really bumped up my understanding.

Best of luck.

 

[starstruck_]

You need to be able translate the equations to pictures of physical phenomena.

When you see a del operator operator you should see a point with arrows pointing away from it (or towards the point if it's negative)

When you see a curl you should a bunch of arrows revolving about some center (pointing the other way if it's negative).

When you see flux you should see a bunch of arrows hitting the top of a surface at some angle.

The book div,grad,curl might be good for getting a physical picture attached to the equations:

https://www.amazon.com/dp/0393925161/?tag=pfamazon01-20

I struggled with E&M before too but trying to translate the equations in the way I'm talking about really bumped up my understanding.

Best of luck.

Thank you so much! As well as everyone else! I’m going to try to put this to use. Also, I lied I don’t understand what we just learned today- it was something about the probability wave and uh I don’t understand (it is intro physics so maybe I’m not supposed to get it?)

 

[StatGuy2000]

@starstruck_ , if you don't mind my asking, what would you say would be your strengths in terms of learning? What areas of physics (if any) do you find relatively easy to grasp? Does math (whether it be calculus/analysis, linear algebra, or other areas of math) come easy to you, or do you need to work on that? Also, how do you learn -- do you learn by listening, or by reading?

In any subject you study, those are among the questions you need to ask yourself. And in those areas where you identify your weakness, you should spend extra time practicing on those so that you can strengthen your weaknesses.

Otherwise, I pretty much concur with what others have posted here in this thread. Just my 2 cents worth.

 

[starstruck_]

@starstruck_ , if you don't mind my asking, what would you say would be your strengths in terms of learning? What areas of physics (if any) do you find relatively easy to grasp? Does math (whether it be calculus/analysis, linear algebra, or other areas of math) come easy to you, or do you need to work on that? Also, how do you learn -- do you learn by listening, or by reading?

In any subject you study, those are among the questions you need to ask yourself. And in those areas where you identify your weakness, you should spend extra time practicing on those so that you can strengthen your weaknesses.

Otherwise, I pretty much concur with what others have posted here in this thread. Just my 2 cents worth.

So far, mechanics has made the most sense to me (then again I learned it in first semester of grade 12 and then spent my spare in second term in the second term physics class, so I had done it twice before uni but hadn’t touched a single bit of electricity). For E&M I think my weakness is a combination of my math and conceptual understanding - mostly me not being able to visualize concepts and getting irritated because they won’t click with me right away.

The integrals and stuff are fine but we haven’t learned line integrals or closed surface integrals and such so I don’t understand how the math works (until my third year friends teach it to me ).