+sharpenednoodles Thank you so much for the feedback!!

whether*

coloring of wires*

Awesome! It's one of those things that seems almost childish, but it really works to help break down the circuit. The same idea can help when setting up circuits in labs, too. I should make a video of that some time... :-)

Yes it's really really work and so effective! I'm using that technique since I watched this video and it really helped me a lot with my electric circuit realate subjects!

That's so great to hear! You rock!!

Fantastic! I'm glad to help. Good luck with your course!

+Francisco Borges Thank you so much! I really appreciate it!

+Samuel Drai Thank _you_ for the feedback, and good luck with physics!

+greyosw22 Fantastic! I'm glad to be able to help, and I really appreciate you taking the time to let me know!

Glad I could help! I'm on vacation for another couple of weeks so I suggest you check out this forum: www.physicsforums.com/forums/homework-and-coursework-questions.152/ They have a framework for submitting your question which seems tedious but actually helps you learn it faster & better than if someone simply answers your question. Good luck!

Thank you very much

I'm glad to hear it. Best of luck to you!

Ha ha... thanks! Do you have any particular problems you'd like me to work through? I'm always looking for specific ideas for my videos, and I haven't chosen my topic for next week's (Oct 18, 2016) webinar yet. You can submit problems to info@redmondphysicstutoring.com. In the meantime, good luck and thanks for your comment!

Thevenin Equivalent Circuits

Okay, I'll dig up an example for next week's webinar. If you'd like to attend live, you can register at www.redmondphysicstutoring.com, or you can also just wait for the recording to be posted on KZfaq.

Hey Keston, I've prepared an example for tomorrow's webinar, but in the meantime you might like the following URLs: Rough overview of the process: hyperphysics.phy-astr.gsu.edu/hbase/electric/thevenin.html hyperphysics.phy-astr.gsu.edu/hbase/electric/norton.html Some nice worked examples: people.clarkson.edu/~jsvoboda/eta/dcWorkout/thevenin.pdf www.calvin.edu/~svleest/circuitExamples/TheveninNorton/ These aren't in any of my introductory physics textbooks, and since I haven't taught it I'm not an expert. Sometimes that makes my explanations better, though, since I can see what it's like from a typical student's perspective.

Hi Keston, FYI I recorded an example showing how to calculate the Thevenin equivalent circuit. You can find it on KZfaq here: kzfaq.info/get/bejne/oraUgc9jr5a4qZs.html I hope that helps! If you have any more specific requests, let me know and I'll try to fit them in.

+Abd Barakat I'm glad I could help. Thank you for the feedback!

If the resistors are all grouped together, you can replace them with an equivalent resistance to help simplify the circuit. If the voltage source, current source, and inductor are mixed up with the resistors, then you'll have to analyze the whole circuit. Good luck!

+Vimal raj You're welcome!! Thank you for the feedback!

It's possible to build each of these circuits in real life, and the voltage and current measurements will match what we can predict via theory. So it depicts how the current actually flows.

@@RedmondPhysicsTutoringVideo ie that current will flow from b to R2 R1 a on the other side from b to R5 R7 , at R7 it will go parallel split to R346 and the current from R1 will will split towards R4 and R3 ( parallel) and R6 will serve as parallel to R3 , so R346 facing current flow from both sides and concentrates on point a before entering the + end, but wont bidirectional current nullify the circuit ?

You have the right idea, that electrons will flow from b to a on both 'sides' of the circuit. The flow into the junction at point a adds up before going to the emf. You can think of it like water flowing, where small streams can add to form a bigger river. The emf acts like a charge escalator, pushing electrons towards the negative end. These electrons find their way through the circuit to the positive end of the emf. It's just like water flowing downhill. Sometimes islands form inside of rivers, and the current flows on both sides of the island and then rejoins.

Yes it does, because each colour represents a wire (or connection of wires) that are all at the same potential. That said, there are some combinations of circuit elements that are neither in series nor in parallel and these combinations require different methods to simplify. That's beyond the scope of introductory courses though and at that point your prof or TA should be able to give strategies and specific advice. Good luck!

Then the algebra gets tricky because you'll need to keep it as an unknown R in your equations. Even that gets easier with practice. Good luck!!

R1 and R2 are in series because any electron that passes through R2 must also pass through R1. There are no other routes for the electricity to flow. Does that help?

So you meant that the right wire of R1 & R2 doesnt let it connect each other and then they have only one way ?

Hmm... Maybe watch it again. The definitions of parallel and series are _very_ specific so you'll need to go through the (sometimes frustrating) work of rewiring your neurons so that you can get these questions correct on exams and/or discuss these terms with other scientists. Best of luck to you!

I'm not sure I understand. Do you mean a short-circuit? If there's a short, you can treat the short as a continuation of the wire - so the wires connected by the short become a single wire. I could do an example with a switch, but maybe that's not what you mean...

+Redmond Physics Tutoring yeah,i will be greatfull if you give me an complex example so that i can understand short-circuit easily

Okay, I looked at an example of short circuits in this week's video: kzfaq.info/get/bejne/ZpN_nbJivrynm6s.html I suspect that won't really answer your question though. If you can be more specific I can give it another try. The best would be to email me a picture of a problem that you're struggling with. :-)

i don't have your e-mail so that i can e-mail the photo to you :(

No problem: info@redmondphysicstutoring.com

+varun sai I'm not sure what to say... it works for me and a lot of other people, at least at the introductory physics level. I only recently encountered a case in which this method doesn't work: resistors set up along the edges of a 3D cube. There could very well be even more cases in which it doesn't work. Regardless, good luck!

i am talking about a case where there is triangle inside another triangle thats becoming more complicated nothing are like parallel or series DO you have any easy method for such situations?

+varun sai I'm sorry, but I don't have any easy methods for such situations... I would imagine you need to consider symmetry. These examples never came up at the level I was teaching.

Maybe he's talking about Kenelly Theorem

Yes, that would make sense. Thank you for pointing that out! We never got to that in the college classes I taught, and I can see it being very helpful when solving complex circuits.

Yeah, I was trying hard to make these videos play quickly. If it helps, you can play it back at 0.5 or 0.75 speed (click on Settings, then Speed). Best of luck in your physics course!

@@RedmondPhysicsTutoringVideo thank you again this video help a lot.