Oh, man! Absolutely genius! Got badly stuck in a problem from chapter 11 of DJ Griffiths, Electrodynamics on finding torque on magnetic dipole due to surface currents. Thanks, buddy, for rescuing me after 5 hrs of struggle. ❤️ from India.
@@PhysicsNinja ❤worth it to go through this masterpiece! It seems the universe wants some of us (and generations to come maybe > 1000 yrs) to enjoy it!😄
i get how the field point horizontally at any point, but shouldn't the magnitude get weaker as u get farther away from the sheet? The final expression does not depend on z which doesn't make sense...
You’re right that in real life this doesn’t make sense but keep in mind that this in an infinite sheet which also doesn’t make sense. It’s like gravity being constant .... it’s true only near the surface or the electric field produced by a plate is also constant (gauss’s law)
Not for this infinite-sized sheet but the only thing that I am stuck at is why we cannot use Ampere's law for a rectangular 2D current sheet one side of infinity and the other of the length of d Anybody who can explain is appreciated
for 6:06, The real reason ,why in 2 and 4 numbered side magnetic field is perpendicular to the side,is wrong i guess. The real reason is there are currents in right and left of second side. Due to this currents, in right side currents apply -B.dl and in left side currents apply B.dl so total B.dl will be zero. Am i wrong and why?
Well no, it is B(dot)dl right. So the dot product will be zero because they are perpendicular. So the original reasoning was right. Current flowing through 2 and 4 does not directly imply a magnetic field density associated with it. dB vector is proportional to the cross product of (I dot dl) and distance vectors. So if I dot dl is 0 --> dB is also = 0. Hope you got it
For method 2, for the right side of the sheets of current, why is it X instead of X/2? Isn't the full length of the sheets of current supposed to equal X?
@@PhysicsNinja Thanks a lot but can you share a solved example related with it. For example assume you have ten parallel current carrying wires near to each other and their lengths are 10cm and you are trying to find the magnetic field 1cm above the sheet.
I have a problem that asks us to measure the magnetic field infinitely close to the infinite current sheet. We can see here that the magnetic field has a clear value going one way or another depending on whether we are above or below the sheet. But if we are exactly on the sheet, does the magnetic field go to zero?
It could be infinite, we can think the infinite sheet of current as many infinite straight wires kept laterally together, the point on that sheet could then be viewed as it is kept an infinite straight wire and as the distance between the infinite straight wire is zero from the expression for field due to a straight wire(long) It will approach infinity. I'm not sure though I made it up just now.
Just had an online exam with this question, you're definitely the best teacher
Dude you definitely are THE GUY man! I'll follow you even after I complete my high school
This problem is literally in my book
You're soooooo useful keep going
Lifesaver (hugs and kisses hugs and kisses)
my professor this semester was really, really bad. thank you for saving my gpa
Happy to help.
Undergraduate student?
wow extremely clear, didn't fully understand it even though i saw my lecture twice until i saw your video sir!
Glad it helped you understand things better.
You're helping people from all over the world. Thanks from Istanbul Technical University, Turkey.
Add Ben-Gurion University, Be'er-Sheva, Israel to the multinational student viewer base.
You sir deserve the whole world. Thanks a lot, very well explained.
Thank you so much man!! ❤️I was badly struggling to visualise this…
Oh, man! Absolutely genius! Got badly stuck in a problem from chapter 11 of DJ Griffiths, Electrodynamics on finding torque on magnetic dipole due to surface currents. Thanks, buddy, for rescuing me after 5 hrs of struggle. ❤️ from India.
Griffiths brings back a lot of memories.
@@PhysicsNinja ❤worth it to go through this masterpiece! It seems the universe wants some of us (and generations to come maybe > 1000 yrs) to enjoy it!😄
Wonderful explanation
❤ From India
found this in the nick of time. got an assessment due later today and this helped a bunch with it. Thanks a lot!
Thank you physics ninja
Love from India
Awesome explanation.thanks.
Good energetic teacher 💪
Thoroughly explained, thank you!
Dude, you are awesome! An education Ninja.
Awesome video
Thanks man, solid stuff and clear explanation
Nice explain like ninja 😉
Could you have solved this problem with method #2 using Bio Savart law ?
You are amazing tutor
Dankuwel meneer
Very Nice explanation. Thank you.
Simply the GOAT.
You really deserve more likes
Beaaasttttt. Took you 11 minutes to explan what my professor at a sub 20% acc rate university took an hour to do
It’s not his fault, he’s just a professor, not a Ninja.
thankyou so much sir
Well done! Thank you for your help!
Thank you so much sir😍
Most welcome
Just Perfect 👌
U solved my problem
How does this work when you have two parallel plates?
Thanks a lot
i get how the field point horizontally at any point, but shouldn't the magnitude get weaker as u get farther away from the sheet? The final expression does not depend on z which doesn't make sense...
You’re right that in real life this doesn’t make sense but keep in mind that this in an infinite sheet which also doesn’t make sense. It’s like gravity being constant .... it’s true only near the surface or the electric field produced by a plate is also constant (gauss’s law)
Thanku
Thx bro 👍
You solved my problem thanks a lot
Not for this infinite-sized sheet but the only thing that I am stuck at is why we cannot use Ampere's law for a rectangular 2D current sheet one side of infinity and the other of the length of d
Anybody who can explain is appreciated
Should it not be B(y) instead of B(z) since the magnetic field points in the y direction ?
thanks dude u the best
Bhai thank you Bhai thank you
Maybe I missed something, but isn’t current equal to J•dA?
Coz, thickness is been ignored
for 6:06,
The real reason ,why in 2 and 4 numbered side magnetic field is perpendicular to the side,is wrong i guess. The real reason is there are currents in right and left of second side. Due to this currents, in right side currents apply -B.dl and in left side currents apply B.dl so total B.dl will be zero. Am i wrong and why?
Well no, it is B(dot)dl right. So the dot product will be zero because they are perpendicular. So the original reasoning was right.
Current flowing through 2 and 4 does not directly imply a magnetic field density associated with it. dB vector is proportional to the cross product of (I dot dl) and distance vectors. So if I dot dl is 0 --> dB is also = 0. Hope you got it
congrats ,you got a new subscriber!
Awesome!
For method 2, for the right side of the sheets of current, why is it X instead of X/2? Isn't the full length of the sheets of current supposed to equal X?
thank uuuuuu
I thought the cancel out should be horizontal not vertical. Can u explain please
why doesn't the y component cancel with the other points?
What about if the sheet is finite in length?
Then the field will depend on position and you’ll need to use Biot-Savart to calculate the field at a specific point.
@@PhysicsNinja Thanks a lot but can you share a solved example related with it. For example assume you have ten parallel current carrying wires near to each other and their lengths are 10cm and you are trying to find the magnetic field 1cm above the sheet.
I have a problem that asks us to measure the magnetic field infinitely close to the infinite current sheet. We can see here that the magnetic field has a clear value going one way or another depending on whether we are above or below the sheet. But if we are exactly on the sheet, does the magnetic field go to zero?
It could be infinite, we can think the infinite sheet of current as many infinite straight wires kept laterally together, the point on that sheet could then be viewed as it is kept an infinite straight wire and as the distance between the infinite straight wire is zero from the expression for field due to a straight wire(long) It will approach infinity. I'm not sure though I made it up just now.
Wht if the point is on the y axis, is the answer is the same, can someone answer this pease
🙌🙌
Current density is Current upon area rigth ?
In the case of a 2-D sheet it’s current per unit length.
@@PhysicsNinja ohh thanks
❤
can you do one with a 3d current sheet?
sorry why is the current density A/m and not A/m^2
Surface current density K is the amount of current flowing per unit length in a direction perpendicular to the flow.
K = dI/dL
So, its unit is (A/m)
are you even a real ninja?? why aren't you wearing black?? dont trust him guys.
Busted.
❤