You're not just make educational video's, you even answer 100 of questions in the comments! What kind of teacher you are?! Where you get this patience and passion from. Amazing!
Just commenting to say you're videos has helped me tremendously throughout physics 1 and 2. You go so in-depth compared to other videos that barley scratch the surface of what you actually need to know in order to excel in a competitive environment. You do such a great job in breaking everything down in an clear and concise manner that is understandable and really get down to the meaning as to why things are the way they are in the equations. You are a world class educator, Thank you.
last time in electric field's playlist when you integrated equation for ring it was from 0 to 2π multiplied with x, x being radius why wasn't it the case this time ?
preparing for my magnetostatics midterm, this vid helped me understand biot-savart in a diff, more helpful (to me) way than what was taught in lecture so THANK YOU!!!
I'm confused because the two thetas shown are of unequal value since either geometric corresponding angles or conveptual as theta--> 90 the other approaches 0 making the relation theta and 90-theta which screws up the whole question
thank you so much for your videos! just one question: is r-hat in the direction of r? why then would it be perpendicular to dl? dl at that point looks like it is on the y axis pointing in the -z direction. r-hat looks like it is at an angle of phi from the y-axis pointing toward the x-axis. if r-hat is perpendicular to dl, wouldn't it go straight out parallel to the x-axis and never meat the point on the x-axis?
Thank you for the steady stream of great lectures. In this one, I was wondering why, at about the 6:00 timestamp, you switched the variable of integration replacing dl with d(theta), instead of just continuing on with dl.
Hi I drew a small picture that might help u visualize it? puu.sh/Du23g/6df48cd539.png , probably you already figured thsi out though since it was 5 months ago?
I know in this example there's little room for error in this regard, but how do we know that's dB's direction and not the opposite. I can't figure how the right hand rule applies here.
Magnetic field in y direction being opposite cancels out. Why electric field of a positive charge does not cancel out. Every electric field line emerging from positive charge has equal & opposite electric field line.
Not sure if I understand your question: "Why electric field of a positive charge does not cancel out?" Are you talking about a point charge? Or are you referencing to the charge on the ring?
Hello Sir, I understand that the y-components of the magnetic field cancel out, but I'm having a difficult time visualizing it in my mind since they are not direct vectors. Could you explain it a bit further or recommend a technique for it?
For each small dl current segment, dBy is not zero, but when you add them all up they will add up to zero. Each segment will have another segment directly across which will have a dBy component pointing in the opposite direction and thus they will all cancel each other out in pairs.
You are a king, this video was so helpful and easy to follow, thankyou! To find the B field strength in a coil of N loops would you simply multiply the expression for B(x) by N? Thanks
Watch the video properly. The extra r, comes from the fact that we consider, that cos(a) = a/r, where r is found using Pythagoras theorem. We plug in original, formula to get r^3
One line is drawn from the point of interest to the center of the circle. One line is drawn from the point of interest to an arbitrary point on the circle.
@@MichelvanBiezen oh no no sorry I asked on the wrong video actually I had to ask for a straight finite wire but I commented on coil 's video I was looking for that straight wire video of you but I couldn't found it that's why I commented here my mistake... I didn't asked properly 🥲 Help me for a straight finite wire meanwhile thank you for responding ❤
@@MichelvanBiezen I have also seen your video for a force on a moving charge that video just literally saved me I was struggling with that part always writing wrong directions it's so sad that in India we don't have professors like you 😭
I would like to thank you very much Professor on this wonderful lecture, I have a question is if the wire is used in the form of a straight line, what is the law of magnetic field calculation?
Sorry I'm late to the party. (Great videos, by the way. I refer my students to them. Very helpful.) To the matter at hand: r, (and also r-hat) is(in this example) in the x-y plane, whereas the current loop, and therefore dl, is in the y-z plane. Any two vectors on these two planes will be perpendicular (provided they intersect like r and dl).
Cross product look at biot savat law. The X between current vector and r unit vector direction indicates that b field is perpendicular to the "plane" of the I vector and r unit vector. Look up cross product i X j = k
Is it just me or do they not look perpendicular to each other on the graph? Isn't dl horixontal and doesn't the unit vector go to the left and down, making the angle between them look greater than 90?
Abdelrahman is correct. r, (and also r-hat) is (in this example) in the x-y plane, whereas the current loop, and therefore dl, is in the y-z plane. Any two vectors on these two planes will be perpendicular (provided they intersect like r and dl).
I would like to give one exercise Sorry challenge 😉😁 problem.. How would we find magnetic field on a point above the loop,but at other than "axial' points Thank you
Here are examples in the same playlist of off-axis points: Physics - Magnetic Field Generated by Moving Charges and Currents (4 of 12) Physics - E&M: Magn Field Generated by Moving Charges & Current (16 of 28) B=? Off-Axis Current Segm
You're not just make educational video's, you even answer 100 of questions in the comments! What kind of teacher you are?! Where you get this patience and passion from. Amazing!
He is God's agent. Educating us. 🙏
Just commenting to say you're videos has helped me tremendously throughout physics 1 and 2. You go so in-depth compared to other videos that barley scratch the surface of what you actually need to know in order to excel in a competitive environment. You do such a great job in breaking everything down in an clear and concise manner that is understandable and really get down to the meaning as to why things are the way they are in the equations. You are a world class educator, Thank you.
Cecilia,
Thank you for your comment.
This man is the best person on youtube.
We are glad you think so. Thank you.
last time in electric field's playlist when you integrated equation for ring it was from 0 to 2π multiplied with x, x being radius
why wasn't it the case this time ?
How the parameters are labeled is not important and the technique of solving these types of problems should be similar.
@@MichelvanBiezen thanks again
This video called "super help", Thanks for helping me to understand more about biot-savart law, Sir. :)
preparing for my magnetostatics midterm, this vid helped me understand biot-savart in a diff, more helpful (to me) way than what was taught in lecture so THANK YOU!!!
These are some beautiful equations.
sir, that was really hard to understand but will try hard to get it.. Thank you!
how it is possible to find the vector potential in this case?
I'm confused because the two thetas shown are of unequal value since either geometric corresponding angles or conveptual as theta--> 90 the other approaches 0 making the relation theta and 90-theta which screws up the whole question
For the picture of the video(blue text), there should not have a pi in the B formula, so it should be (I)/2R.
thank you so much for your videos! just one question: is r-hat in the direction of r? why then would it be perpendicular to dl? dl at that point looks like it is on the y axis pointing in the -z direction. r-hat looks like it is at an angle of phi from the y-axis pointing toward the x-axis. if r-hat is perpendicular to dl, wouldn't it go straight out parallel to the x-axis and never meat the point on the x-axis?
You have helped me out again prof😌⭐
Glad we did. Thanks for the comment.
What if we were looking for the magnetic field smack in the center of the loop, and not on any axis per se?
Do we simply give r the value of zero?
The center of the loop would still be on the axis with x = 0
And retain the 'r' components, I take it then?
Since r is converted to a and x it is better to consider those
understood :)
Thank you for the steady stream of great lectures. In this one, I was wondering why, at about the 6:00 timestamp, you switched the variable of integration replacing dl with d(theta), instead of just continuing on with dl.
l = r0 dl = rd0 ;r is constant and 0 is theta
I cant visualise how fi from the loop ends up at Point P any help would be appreciated! 2:05
Hi I drew a small picture that might help u visualize it? puu.sh/Du23g/6df48cd539.png , probably you already figured thsi out though since it was 5 months ago?
Thank you very much for the arc length concept applied here.
But why we have to use unit vector r along the r vector in the formula instead of the r vector???
Every vector is expressed in terms of its magnitude and direction. The r unit vector indicates the direction of the r vector. (ex: 3 i + 5 j )
@@MichelvanBiezen ohh thanks for the explanation.
Sir, how can we solve this problem using Ampere's law?
I know in this example there's little room for error in this regard, but how do we know that's dB's direction and not the opposite. I can't figure how the right hand rule applies here.
Magnetic field in y direction being opposite cancels out. Why electric field of a positive charge does not cancel out. Every electric field line emerging from positive charge has equal & opposite electric field line.
Not sure if I understand your question: "Why electric field of a positive charge does not cancel out?" Are you talking about a point charge? Or are you referencing to the charge on the ring?
Hello Sir, I understand that the y-components of the magnetic field cancel out, but I'm having a difficult time visualizing it in my mind since they are not direct vectors. Could you explain it a bit further or recommend a technique for it?
Do you have another example where the current loop is half circle? We would have to calculate the y component because they would not cancel?
Take a look at this one: Physics - E&M: Electric Field (11 of 16) An Arc of Charge ua-cam.com/video/p-W2mKDgbbs/v-deo.html
hello sir can we show that at y component the dBy = 0 showing the calculation
For each small dl current segment, dBy is not zero, but when you add them all up they will add up to zero. Each segment will have another segment directly across which will have a dBy component pointing in the opposite direction and thus they will all cancel each other out in pairs.
@@MichelvanBiezen yes sir I agree but can we show the solution
If you were my physics teacher...I'd ace physics forever
Thank you for the confidence!
I missed the point at 6.03 about why dl is (a)(sine theta)
Think of the arc length of a circle s = R x theta Here dL = a x (d theta)
@@MichelvanBiezen I got it. Thank you so very much!
You are a king, this video was so helpful and easy to follow, thankyou! To find the B field strength in a coil of N loops would you simply multiply the expression for B(x) by N? Thanks
+Nick Tyler
Yes, simply multiply by N
Can someone explain to me why for dBx it is r^3 underneath instead of r^2?
Watch the video properly. The extra r, comes from the fact that we consider, that cos(a) = a/r, where r is found using Pythagoras theorem. We plug in original, formula to get r^3
Hey i have a doubt , how you decide from which point you have to draw the lines for taking angles its very confusing please help me ❤
One line is drawn from the point of interest to the center of the circle. One line is drawn from the point of interest to an arbitrary point on the circle.
@@MichelvanBiezen oh no no sorry I asked on the wrong video actually I had to ask for a straight finite wire but I commented on coil 's video I was looking for that straight wire video of you but I couldn't found it that's why I commented here my mistake... I didn't asked properly 🥲 Help me for a straight finite wire meanwhile thank you for responding ❤
@@MichelvanBiezen I have also seen your video for a force on a moving charge that video just literally saved me I was struggling with that part always writing wrong directions it's so sad that in India we don't have professors like you 😭
Hey why are some problem having r^3 instead of r^2?
It depends on the format of the equation. Note that there is a unit vector in the numerator. Compare that to the other equations.
Thank you for clarifying this so well!
I would like to thank you very much Professor on this wonderful lecture, I have a question is if the wire is used in the form of a straight line, what is the law of magnetic field calculation?
Same principals apply. Find your B field at some point P for some Dl on the line of charge, then integrate that over the length of the line.
Sir why the angle between r and dl is 90 not phi , I didn't get it
Any vector pointing away from a line will always be perpendicular.
thank you Sir
Sorry I'm late to the party. (Great videos, by the way. I refer my students to them. Very helpful.) To the matter at hand: r, (and also r-hat) is(in this example) in the x-y plane, whereas the current loop, and therefore dl, is in the y-z plane. Any two vectors on these two planes will be perpendicular (provided they intersect like r and dl).
the angle between r and dl is given in theta, not phi
Thank you very much for your efforts in making the video very thoroughly. It's so helpful and easy to follow. A superb video indeed, sir!
Can you explain why we ignore the other part of the moving charge’s path
This method is representative of any part of the charge's path. You would get the same result for any part.
Michel van Biezen ohh that makes sense. Thank you!
why in the video where u used bio-savart in a line segment =2a you didnt take into account dbx and dby?
We did take into account the dBx (the dBy terms cancel).
then y did u use sine instead of cosine?
Didn't we use the cosine in the equation?
u used sine and made R/r ???and then substitute into the equation
Sir you are AMAZING!
Thank you kindly!
Hii Sir..
I cannot understand how u got the direction of B field. How comes B direction is perpendicular to R direction?
Cross product look at biot savat law. The X between current vector and r unit vector direction indicates that b field is perpendicular to the "plane" of the I vector and r unit vector. Look up cross product i X j = k
If Cosine= adjacent/hypotenuse, should it be x/r rather than a/r?
+jandon603
Not for the angle indicated. The video is correct as is.
Thank you sir, a great help as usual 🙏
Always welcome
@@MichelvanBiezen 💜
Thank you very much for the video but why is the a distance r equal to 1?
Marcus Cowan
Any unit vector has the length of "1"
Okay thank you
Why y-component of db cancels each other?
Because when you integrate that component over the 360 degree circle you will get zero. (each component has a counterpart in the opposite direction)
You are amazing ... keep going
Sir, did u assume that the angle between the (I dL) and (r) is 90
because the Dl is in the Z direction? and R is in the XY plan?
+Abdelrahman Wael Helaly dl and r are perpendicular to one another (90 degrees). r is the position vector
Is it just me or do they not look perpendicular to each other on the graph? Isn't dl horixontal and doesn't the unit vector go to the left and down, making the angle between them look greater than 90?
Abdelrahman is correct. r, (and also r-hat) is (in this example) in the x-y plane, whereas the current loop, and therefore dl, is in the y-z plane. Any two vectors on these two planes will be perpendicular (provided they intersect like r and dl).
@@markphilippi8558 thanks
Thank you so much im dying with my midterm
I would like to give one exercise Sorry challenge 😉😁 problem..
How would we find magnetic field on a point above the loop,but at other than "axial' points
Thank you
Here are examples in the same playlist of off-axis points: Physics - Magnetic Field Generated by Moving Charges and Currents (4 of 12) Physics - E&M: Magn Field Generated by Moving Charges & Current (16 of 28) B=? Off-Axis Current Segm
That was awesome.. thanks man!
Thx, the videos helps alot !! appreciate it
amazing video
i love your videos man but how tf is that an r
Yes my small "r" looks a bit funny.
amazing! thank you
Thanks so much sir 👍