great video. My textbook explains every little single detail and doesn't clarify what info to focus on, but this video helps in simplifying the material I read.
@wcsummer the FBI rule applies for the Left hand. Sal is using the right hand rule: thumb = force, 1st finger = velocity of proton 2nd/middle finger = field it's just the same idea! haha but check it out! if you apply the FBI rule, your force (thumb) still points upwards, just like the right hand rule Sal used!
Why are so many khan academy videos only available in 240p? Don't get me wrong, I love these videos! I just think it is much easier on the eyes to have them in 720p or something
He's got the rule wrong, the fingers should be force, field and current in that order and used with the left hand rule as the left hand rule is for conventional current but he has got the order of the fingers muddled up so his way works with the right hand rule.
I'm a little confused. According to Wikipedia, the thumb is Force, index finger is mag field, and the middle finger is the current. This follows the FBI rule. In this video, the current and field fingers are switched.
The vector "l" is a vector of displacement not distance. Distance is the magnitude of the displacement. I always got confused because I thought for a long time they were the same thing until I read the first chapter of a physics book all over again.
I believe the thumb is the force/ motion, the first finger is the field and the middle finger is the current? Also, you use the left hand rule for conventional current and right hand if you want to use the flow of electrons.. I think you should clear up this confusion! Your way does work but it's not the actual right hand/ left hand rule, for this you should be using the left hand rule as the current is the conventional current direction, and F,B and I in the right order.
Thank you so much! This is such a relief. I was stressed about my physics exam but now I know that I will at least have a basic understanding and not be completely lost! So thankful to be living in a time where I have youtube and khan academy! :)
@@hisyamhasbi8257 Yes, its just a matter of convention that we imagine that its the proton thats moving and not the electron. When in reality the electron is ALWAYS the one moving, unless we are talking about plasma, which is not the case here. The reason we imagine that it is the proton thats moving is because of historical reason, but then when people noticed that it was wrong, they didnt care for changing it since we can always imagine that its the electron moving and not the proton. Hope this helps, if not, do not hesitate to ask for more clarificiation
I'm watching all these. You ever consider that this is the equation of the big bag, black holes and galaxies? Well you're helping me understand it that way. This plus vortex mathematics and David Bohm's maths and structure is the full picture. You're a very good teacher by the way. I'm leaning a lot of very complex stuff through you.
@khanacademy Dear Drs. Khan, Could you please elaborate the left hand rule? Where you applied the right hand rule in this video, We were taught to use the left hand rule. I live in the Netherlands. This could be the reason for these differences. Thank You So Much!
I know this is 10 years late but the left hand rule is used for electric motors (where thumb - direction of thrust on the conductor, index - direction of magnetic field and middle finger - direction of current) while the right hand rule is used for electric generators (where thumb - direction of motion of the current, index - direction of the magnetic field and middle finger - direction of induced current). However these are not actually used, but what is the Lorentz Force formula
Because electrons are moving in the opposite direction of current. You can use a "left hand rule" for negative charges and see that its the same as what sal did.
@purplepick1 Dont worry. Sal explains 100x better than any textbook or an average physics teacher. Just start again form video 1. Dont lose patience. I am sure u will get it.
You should use the left hand rule or right hand screw rule to explain the force direction. The direction of LxB should points to the left downward side (penperdicular to the length vector)
Sir, I think you've done a mistake in finding the direction of the force on the conductoryou took the direction of magnetic field as second finger, while its actually the index. So, the force is opposite to the direction of what you've shown in the vedio. And, I'm not sounding rude.... Peace
FiscoDiaz i=current, but current is defined to be the opposite direction of the flow of electrons. So your velocity vector is actually in the opposite direction which cancels the negative charge.
So what does this force do? Doe it move the wire? Does it affect the current in the wire? Does this force affect anything. What kind of force is it? It would be great if you described what this force does. Force tends to do work. Thx
Thanks. Its very benificial. I will always remember your contributions. I was trying to understand in the way it is given on the book, but it made me confused. After watching your video my confusion is cleared. Great job and well done
My experment in magnatic field as follow:- I get two shaft of iron the diameters of it about 3cm I made cone in end of each one in its head now its head coney of each one.the cone hight is 15 cm Now i put each cone head contact the other By its knifey age. Now i made magnatic flux by coils each shaft has coil. Both coils operate that making flux in one direction passing through the contact point when i made (on) to electric power theres Light came from contact point. The properties of each coil as Follow:- no. Of turn is 2500. Diameter of wire is one mm Power is 220 v.
Well, I am sorry that I am not the quickest learner here.. Does it not have to apply Flemming's left hand rule to determine the force on a current carrying conductor in a magnetic field.. and if YES then the direction of current should be downwards... Please, can some clarify that..
yes they do, but this video is the force on the wire due to the external magnetic field. The force that is a result of the field that the wire creates does not affect the wire it self.
So with some really strong batteries and some wires running around your body you should be able to apply currents that generate forces that will enable you to fly in Earth's magnetic field. Cool huh?
wiki is probably explaining the curling method - there are various ways to use the RHR. Either that - or someone screwed wiki up. (anyone can edit it you know?)
So, we must be saying that this wire is suspended between two halves of a magnet, right? I get a little confused because the current itself will induce a B going counterclockwise around the wire due to right hand rule where you curl your fingers around the wire (are there names for the different right hand rules?!) So won't that B-induced due to current counteract some of the magnetic field around it?
Lets give it up for the most awsome person on youtube!!! No not me ;) YOU!!!!!!! Thank you soooo much, i DID have problems with magents, dont anymore :P
@devs604; and let me tell u he is 100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000,better than my teachers they speak urdu and dont get a word cause understand english better but though sindhi........... well thanks khan uncle................
of course he is better than your physics professor... that is the whole point of the internet. we can sit at our computers and find the greatest minds in the world. formalized education is a narcotic worse than opium. our society needs to find a new babysitter for our children until they are 18 or just throw the babysitter away.
At 5:30 he explains the fundamental theorem of quantitative financial analysis as well, what an amazing teacher
frysebox1 lol
great video. My textbook explains every little single detail and doesn't clarify what info to focus on, but this video helps in simplifying the material I read.
Murphy08 which book u use?
What book do u use
@wcsummer
the FBI rule applies for the Left hand. Sal is using the right hand rule:
thumb = force,
1st finger = velocity of proton
2nd/middle finger = field
it's just the same idea! haha
but check it out! if you apply the FBI rule, your force (thumb) still points upwards, just like the right hand rule Sal used!
Why are so many khan academy videos only available in 240p? Don't get me wrong, I love these videos! I just think it is much easier on the eyes to have them in 720p or something
recording is from 2008
He's got the rule wrong, the fingers should be force, field and current in that order and used with the left hand rule as the left hand rule is for conventional current but he has got the order of the fingers muddled up so his way works with the right hand rule.
I'm a little confused. According to Wikipedia, the thumb is Force, index finger is mag field, and the middle finger is the current. This follows the FBI rule. In this video, the current and field fingers are switched.
The vector "l" is a vector of displacement not distance. Distance is the magnitude of the displacement. I always got confused because I thought for a long time they were the same thing until I read the first chapter of a physics book all over again.
Luna@ yaa...physics works on basics
I believe the thumb is the force/ motion, the first finger is the field and the middle finger is the current? Also, you use the left hand rule for conventional current and right hand if you want to use the flow of electrons.. I think you should clear up this confusion! Your way does work but it's not the actual right hand/ left hand rule, for this you should be using the left hand rule as the current is the conventional current direction, and F,B and I in the right order.
Thank you so much! This is such a relief. I was stressed about my physics exam but now I know that I will at least have a basic understanding and not be completely lost! So thankful to be living in a time where I have youtube and khan academy! :)
hows life now
how's life now
isnt the force suposed to be oposed because the particles that are moving are electrons and not protons?
I have this exact same question, anyone?
@@hisyamhasbi8257 Yes, its just a matter of convention that we imagine that its the proton thats moving and not the electron. When in reality the electron is ALWAYS the one moving, unless we are talking about plasma, which is not the case here. The reason we imagine that it is the proton thats moving is because of historical reason, but then when people noticed that it was wrong, they didnt care for changing it since we can always imagine that its the electron moving and not the proton.
Hope this helps, if not, do not hesitate to ask for more clarificiation
I'm watching all these. You ever consider that this is the equation of the big bag, black holes and galaxies?
Well you're helping me understand it that way. This plus vortex mathematics and David Bohm's maths and structure is the full picture.
You're a very good teacher by the way. I'm leaning a lot of very complex stuff through you.
I use to think the X meant the arrow was coming at you and the dot meant it was going away, then I took an arrow to the knee
@khanacademy
Dear Drs. Khan,
Could you please elaborate the left hand rule?
Where you applied the right hand rule in this video,
We were taught to use the left hand rule.
I live in the Netherlands. This could be the reason for these differences.
Thank You So Much!
I know this is 10 years late but the left hand rule is used for electric motors (where thumb - direction of thrust on the conductor, index - direction of magnetic field and middle finger - direction of current) while the right hand rule is used for electric generators (where thumb - direction of motion of the current, index - direction of the magnetic field and middle finger - direction of induced current). However these are not actually used, but what is the Lorentz Force formula
Because electrons are moving in the opposite direction of current. You can use a "left hand rule" for negative charges and see that its the same as what sal did.
@purplepick1 Dont worry. Sal explains 100x better than any textbook or an average physics teacher. Just start again form video 1. Dont lose patience. I am sure u will get it.
You should use the left hand rule or right hand screw rule to explain the force direction. The direction of LxB should points to the left downward side (penperdicular to the length vector)
Sir, I think you've done a mistake in finding the direction of the force on the conductoryou took the direction of magnetic field as second finger, while its actually the index. So, the force is opposite to the direction of what you've shown in the vedio. And, I'm not sounding rude.... Peace
I'm from Alberta Canada and this is very identical to our ciriculum, so LUVIN THE KHAN!!
FiscoDiaz i=current, but current is defined to be the opposite direction of the flow of electrons. So your velocity vector is actually in the opposite direction which cancels the negative charge.
So what does this force do? Doe it move the wire? Does it affect the current in the wire? Does this force affect anything. What kind of force is it? It would be great if you described what this force does. Force tends to do work. Thx
Thanks. Its very benificial. I will always remember your contributions. I was trying to understand in the way it is given on the book, but it made me confused. After watching your video my confusion is cleared. Great job and well done
I thought you were wrong when you were drawing the direction of the force... Then I realized I was using my left hand.
My experment in magnatic field as follow:-
I get two shaft of iron the diameters of it about 3cm
I made cone in end of each one in its head now its head coney of each one.the cone hight is 15 cm Now i put each cone head contact the other
By its knifey age. Now i made magnatic flux by coils each shaft has coil. Both coils operate that making flux in one direction passing through the contact point when i made (on) to electric power theres
Light came from contact point.
The properties of each coil as
Follow:- no. Of turn is 2500.
Diameter of wire is one mm
Power is 220 v.
@kkurian10 left hand is for electrons, right hand for protons
Well, I am sorry that I am not the quickest learner here.. Does it not have to apply Flemming's left hand rule to determine the force on a current carrying conductor in a magnetic field.. and if YES then the direction of current should be downwards... Please, can some clarify that..
Hassan Yahya personally I think it's the Flemings left hand rule and direction of current is downward
Velocity is the DISPLACEMENT vector over time.
@boredpeople100
haha, nahh, the curling right hand rule kinda gives you like a "thumbs up" shape, not the one used in this video left or right hand.
Go to The video : Circuits (part 1) you find the explanation of your question.
thanks sal
@kkurian10 All the same rule. But different hands with different fingers representing things.
you are a great teacher man!
Thank you teacher❤ You make me bright
What about the magnetic field that wire creates around itself in concentric circles????
xx xx that is what my concern is...!!! doest the field of wire and external field interfere...plz reply me if u have got the answer to these problem
xx xx isn't this whole force exerted due to the very interaction of magnetic fields of the wire and of the external/horseshoe magnet?
yes they do, but this video is the force on the wire due to the external magnetic field. The force that is a result of the field that the wire creates does not affect the wire it self.
So with some really strong batteries and some wires running around your body you should be able to apply currents that generate forces that will enable you to fly in Earth's magnetic field. Cool huh?
Maybe that’ll be a good idea for a marvel superhero suit haha
wiki is probably explaining the curling method - there are various ways to use the RHR. Either that - or someone screwed wiki up. (anyone can edit it you know?)
Why only indians here 😂😂❤❤
So, we must be saying that this wire is suspended between two halves of a magnet, right? I get a little confused because the current itself will induce a B going counterclockwise around the wire due to right hand rule where you curl your fingers around the wire (are there names for the different right hand rules?!) So won't that B-induced due to current counteract some of the magnetic field around it?
hey do you do organic chemistry as well. im struggling with mechanisms and IR, NMR, and mass spec. just wandering thanks
Genius!!!
If you bring a magnet near a current carrying wire, does the magnet get repelled/attracted (depending on the direction of current of course)?
Agreed, but it's a worthy attempt. As opposed to no education/babysitter at all.
length is not a vector quantity .......... It has no direction ......... Then why we take it as a vector ??????? plzzz tell me Sir .............
What he actually means here is displacement
NOW that makes sense thanks so much I was so confused about length vector@@jayalakshmisharavanan5123
ohhhh i just realized i was using my left hand. lol
Lets give it up for the most awsome person on youtube!!!
No not me ;)
YOU!!!!!!!
Thank you soooo much, i DID have problems with magents, dont anymore :P
down with evil physics professors! all we really need are these youtube videos.
Excellent explanation
what if the magnetic field is parallel to the earth????
2021 anyone??
(serious explanation)....... ANYWAY...my time is up!! LOL
Xddd
Why can we write V as 1/t?
We write v not as 1/t but L/t, or, distance/time, which is velocity
Cihan Barnett its not 1/t but its 1/t * l
Because v/t =(v)*(1/t)
khanacademy, whens magentism 9?
how u took B= IT
@devs604; and let me tell u he is 100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000,better than my teachers they speak urdu and dont get a word cause understand english better but though sindhi........... well thanks khan uncle................
Doing the right hand rule for this field/vector combo it looks like I'm flashing gang signs
This comment made my day XD after stressing out coz of my p6 exams review, im glad this made me laugh so bad.
improve the setup 🙄😳😳
Yup, hes not doing it the 'normal' way, maybe its an American thing..
im so confused... usually i get ur videos but not magnetism...
Val Lumi Its accually pretty easy, the only criticism is that there are too many drawings on the board.
And i don't blame him for it.
of course he is better than your physics professor... that is the whole point of the internet. we can sit at our computers and find the greatest minds in the world.
formalized education is a narcotic worse than opium. our society needs to find a new babysitter for our children until they are 18 or just throw the babysitter away.
Nat G he may be better than your professer , not everyone. he sucks infront of mine and i'mdamn sure of it