Man, these videos should be kept like a treasure to humanity... So amazing, with a wonderful connection to the real world! Honestly that is what I miss the most in my lecture notes... Why not talk about electric motors and TVs like Doc Schuster does? For an engineering student this is a gift that keeps on giving
For 3 hours i was blankly staring at my notes cause it was not making sense and the fact that i understood in less in 13 min is crazy. Sir, you are doing God's work
You are absolutely incredible! I have spent three hours looking through textbooks and google trying to figure out how to solve this problem for my physics class and within 7 minutes of this video you have explained it all in a way that actually makes sense and allows me to solve this problem. Thank you thank you thank you!!!
You are the best professor ever. I struggled understanding the book and my professor in one hour cant do what you did in 12 minutes. Now I understand. Thank you!!!!
@@DocSchuster Which of the following is not a guaranteed way to increase the average torque produced on a loop carrying current? Increase the length of the loop Increase the number of turns Increase the torque angle Increase the breadth of the loop
This was awesome. I mean it definitely helped me understand the whole concept of torque and current but the sound effects..those were the best. Haha thanks! :)
You are so so passionate when you teach and it makes it so much easier to learn. I have managed to learn '10 lectures' worth of Electro Magnetics in under 4 hours with your videos. Thanks so much keep up the awesome work :)
Thank you for inadvertently explaining to me why we say that the current flows out of the positive terminal. I was always confused because I knew that only electrons could move through a wire but you showed me that the current of electrons IS actually flowing against the "current" in the circuit
Uk i almost give up on physics but then never thought that learning from utube makes me easier to understand ahhh thankyou so much for thiss may God bless u. xoxo from a malaysian student
I had never heard of the passive sign convention. Sounds like a great way to get away from the vector nature of these torques. You're right, though, I am glossing over the details in this introduction. I think I did use the RHR a bit...
a little confused. read that you find n^ (or area vector) by the right hand rule.... in this case by curling your fingers along the direction of the current...... then your thumb points in the direction of the area vector. if this is so, then the area vector would be pointed in and not out? (referring to 7:03)
Hi, why wouldn't we consider the centripetal force that acts till we reach the axis of rotation, in that case shouldn't we integrate over width from 0 to w/2?
for the force that is out of the page , why do u use ur left hand to find the force. ? why didn't u use the right hand rule? and why did u use the in term of electrons and not the current? i'm very confused
OMG I have not words to use to thank you for this video, anything would be not enough. But I just going to say it any ways YOUR VIDEO IS AWESOME, THANK YOU SO MUCH FOR THE DYNAMIC EXPLANATION!!!!! YOU ROCK!!!!!!!!
Great video! I was wondering, when, let's say, the loop has rotated around 45 degrees. Now would there not be an EXTRA 2 forces on the horizontal wires because you have now offset their angle from the magnetic field by 45 degrees (up and down)? It wouldn't affect much as long as the wires had a good bending resistance but still.
If we split the circuit in half down the spindle and had a top view, the horizontal wires would have an inward force for the half left of the spindle and outwards on the right half. Cool I hope I got that right
Great video! I understood it till the part where you explained the forces for top view but got confused with the direction for rotation . Why would it stop after turning 90° and try to come back in the opposite direction ? please help
Absolutely. But not until 1879 was that a problem. My students often ask me why we don't just change the direction of conventional current. In the US, we're still using feet and teaspoons to measure stuff like it's 1612. Dang it.
If a current passes through the coil shouldn't it induce a magnetic field on presence of already existing magnetic fields ( the green like that you drew )
Hey, I have a question. Indeed the torque will cause the closed loop wire to rotate, then go past its equilibrium point (where A vector points in the same direction as B) due to its inertia, and so it would rotate in the opposite direction back to the equilibrium point. How does this work for an AC Generator I have been looking for explanations everywhere, and all of them simply assume that the wire turns completely under the influence of the B field. Hope someone can clear my questions.
I'm pretty sure it does just because he wanted it that way. Because the area vector is the cross product between width and length, you can make the area vector either point out of the page perpendicular to the surface, or into the page perpendicular to the surface, depending on what order you cross multiply the vectors. Additionally, choosing to have the area vector point into the page still illustrates his point that the magnitude of torque is maximized when the area vector points perpendicular to the magnetic field.
Why does one of my textbooks say t=Fd sin theta, while another one says that t=nBIA cos theta? I understand how it is BIA, but do not understand why one is sin and the other one is cos!
torque is the rotational motion produced on a fixed axis due to equal and opposite forces exerted by an external agency on the diametrically opposite ends of a body. In this case force is directed upwards on one part of the wire and downwards on the opposite part.
+Chhaya Arora Torque is basically a force that is moving/ rotating around something/object from a distant r=distant between them. Think of the solar system, where Earth is moving from a force exerted by Sun's gravitational pull from a distant of some million mile way. So Earth is experiencing a Gravitational torque from the Sun. I guess see some video about angular momentum to see what forces (torque) could do and if that is helpful.
Excellent tutorial However this seems true for scalars, but not for vectors I assume we all agree that Torque = (Force = current Height X B) X Width However in general (Height X B) X Width doesn't= (Area = Height X Width) X B because vectors in a triple product are not commutative like scalars in multiplication Therefore in general Torque doesn't= [u = current (Area = Height X Width)] X B Pls point out my fallacy, I would love to use this on electric motors theory. Thks TomB
Tom Bouie I figured it out; It's important to note the relative orientation of the Wide, Height, & B field to the spinning rectangle current loop Although Wide&B are not in general perpendicular ; (current Height) & B and (current Height) & Wide are always perpendicular Torque= Wide x (Force= current Height x B) = (Wide dot B) current Height - [(Wide dot current Height)=0] B Torque= (current Area = Wide x current Height) x B = (Wide dot B) current Height - [(current Height dot B)=0] Wide Therefore Torque= Wide x (current Height x B) = (current Area) x B = (Wide dot B) current Height Note (current Height) & B or (current Height) & Wide not being perpendicular doesn't apply to this particular situation at all Thks for the video, TomB
Didn't you use your left hand to determine the force the first time? I think you did. Because when using the right hand, it doesn't give the same direction to the force.
He used his left hand because he was talking about the flow of the electrons, which is opposite to the flow of current. If you match the right hand rule to the direction of the arrow on the wire you'll see that your right thumb goes into the page as well. RH rule for current, LH rule for electrons.
I think your thinking about area vector is wrong. Because as current flows clockwise, the area vector is going to be into the page using the Corkscrew rule. But u said at 7:02 , that it points out of the page. If someone have better explanation, please let me know.
there would be phase cancellation that would (depending on the proximity) would increase double or half the magnetic field. there is 90° that the phase can intersect without problem.
