Faraday's Law Introduction | Physics | Khan Academy
ฝัง
- เผยแพร่เมื่อ 7 ต.ค. 2015
- Courses on Khan Academy are always 100% free. Start practicing-and saving your progress-now: www.khanacademy.org/science/p...
How a current can be induced in a loop of wire by a change in magnetic flux.
Physics on Khan Academy: Physics is the study of the basic principles that govern the physical world around us. We'll start by looking at motion itself. Then, we'll learn about forces, momentum, energy, and other concepts in lots of different physical situations. To get the most out of physics, you'll need a solid understanding of algebra and a basic understanding of trigonometry.
About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content.
For free. For everyone. Forever. #YouCanLearnAnything
Subscribe to Khan Academy’s Physics channel: / channel
Subscribe to Khan Academy: th-cam.com/users/subscription_...
His digital handwriting is still better than my real handwriting...,,,
Too Much Candor he's writing with a digital pen
Digitally
R u still here ?
So why don't you try with your hand😊
I always turn to khan academy videos for better understanding of basic topics, it would be of great help if you have engineering topics too
Great timing ,I'm taking electricity and magnetism and it's great to see you explaining these topics thanks.
Why is current not anticlockwise??? Isn't he using the right-hand grip rule?
actually, by lenz law, if the magnetic flux is increased in a loop, the loop tends to oppose the increase in flux by inducing a current in the opposite direction. so instead of a counterclockwise current, a clockwise current is induced.
Lenz's Law.
Think about it like this:- the square coil is not the magnetic field but the current direction and the magnetic field lines are coming out of the screen,
*Solution:- In this case we can use Fleming's left hand rule, (the last three fingers must be facing upwards if the screen of your device is facing up as well,) and then it's pretty clear what the direction of current should be* :)
yes, please do more on electricity and magnetism. thank you
Will later videos have Maxwell's equations in them?
Is the emf induced pointing upwards to be perpendicular to the B field coming out of the board? Does it conflict with the current flowing down on the right side of the wire?
My cancer has just been cured
mine is likely in the process of manifesting itself as we speak. DNA Polymerase, don't fail me now!
@@StereoSoundAgent what I love about science videos are these nerd jokes
no one ask you simp!!!!!!
I was about to drop the course then i saw this video thanks :)
Does adding more loops also count as changing the area?
In observing the cross section of a magnetic field:
- if the flux is increased in an anterior direction, a clockwise current is induced
- if the flux is increased in an posterior direction, a counter-clockwise is induced
Great work Sal
Conductor+magnetic field+relative motion=induced current. You should do more electrical engineer videos.
yes
Thanks!
pls do more of this. I need to learn more about electrical engineering for robotics club
krozz mds disease
goodman thanks!
In a previous video you showed the direction of current using the right hand rule indicating that it has same direction of the force, but when you increase magnetic flux i cant figure out the direction of force that creates the current
I know this is 4 years late but,
it's because there's two different right hand rules. One for the magnetic field due to a current and another for current due to a magnetic field in a coil.
its good if u r speaking slow bcz we r from dfrnt countries
My favourite teacher 🤘😊
Great lecture
are this the new videos because I see there are older ones?
how does magnetic flux influence current and its direction?
Why do chane in magnetic flux created a induced EMF?
sorry I still dont' understand how to determine the direction of current why it is clockwise?
is that " out of paper " means the current has to be clockwise ?
hery sd ree its clockwise because the magnetic field lines are coming out of the page, and by convention magnetic field lines go from the N to the S. So this means that the north pole is behind all the magnetic field lines, and then if you use your right hand grip rule, you point your thumb into the North which is into the screen, and you curl your hand and then you will be able to realize that the current flows clockwise
thank you man... I appreciate it... !!!!! :D
all goodsss, hope it helped :)
i understood your explanation better than the video lol
@Reflexez not sure bruh i finished year 12 last year. Forgot everything now ahaha
convoluted explanation
to keep unducing current, do we need keep changing the magnetic flux through loop?
yes
Isn't the current actually going in the counterclockwise direction? If you use the right hand rule and point your thumb toward yourself in the direction of the magnetic field, you would curl your fingers in the counterclockwise direction, right?
No, it should be clockwise. Watch the lenz law video
No it's clockwise. Watch the lenz law video
Savannah Patterson agreed...I think it will be anticlockwise direction. Still confused ! 😔
No, he got this correct. Since its increasing you will point your thumb in the opposite direction of the field and curl. Think of it like this when it is decreasing you want to go with it to "help it out".
Savannah Patterson The righthand rule you are referring to is of current (I) inducing a magnetic field (B). so if these vectors were currents you would be right. In this case, though, they are magnetic field lines. So the total B through a coil loop's area is magnetic flux, and the change in that flux induces a current whose magnetic field would oppose the flux (Lenz's Law). I guess you could call that a lefthand rule? lol
Thumbs up if this helps, so that more people can see the difference!
Why is there no induced current to begin with? The Flux isn't = 0, you only have magnetic field lines going one way and none going the other way. I understand that a change in flux induces a current, but you allready have flux to begin with, so what's going on? I feel like this topic isn't explained very well by most people.
@ 2:53 - why does the current go clockwise?
How do you know which direction the current is going?
Lenz law
Only when the magnetic field intrinsically changes does it cause an emf in the coil. Any change in the flux due to motion of the coil has no effect; the emf is produced by the motion of the wire through the magnetic field. Faraday's Law obfuscates the principle involved.
It seems that Physicists are not making a distinction between math and physics. According to math, moment and work are equivalent; they are measured in the same units. Faraday’s Law can be derived, but derivation is math. Math is not physics. A physical law cannot be derived; it can only be discovered empirically.
Faraday's Law is superfluous. It serves no useful purpose. It only serves to confuse people, and it is the worse kind of confusion because the people do not know that they are confused. Every case of induction is covered by either (or both) principles of induction: motional emf, which deals with motion, and the Maxwell equation known as the Maxwell-Faraday Law, which deals with intrinsically changing magnetic fields.
Exam not fear is so best
If the magnetic field is uniform and the wire loop is moving at a constant velocity in the field, there will be no e.m.f induced in this case. Is this right?
the magnetic field isn't uniform here. when he moves the loop to the left, the magnetic field is becoming stronger.
@@laksheya IF the magnetic field is uniform
And if the magnetic field is uniform, and the wire loop is moving at a constant velocity, there will be no EMF induced in the wire loop, since the magnetic flux moving through the wire loop is constant
@@solcoster8110 oh sorry, i thought op was talking about what was happening in the video. you're right!
i don't get it. I think this one is drawn odd. I'd like to see a bar magnet going into the wire loop from the side not having the flux coming at me which is hard to draw because it then moves to the outside , takes a hook back toward the black board, then hooks back around and into the magnet again. I just couldn't grasp this drawing.
Thank you for this video.
This is technically just called Lenz law.
what happens when you have a loop (with no external voltage applied) inside of an unchanging magnetic field?? will there be current induced in the loop?
nope, current is induced with a change of flux. Unchanging magnetic field = no change in flux unless you move the loop around
When a loop is placed stationary in an unchanging magnetic field, current will NOT be induced in the loop
You need a constantly changing magnetic field through the loop, to induce a current within the loop
Where are the equations?
But how does a changing magnetic field induce an electric current? What’s the physics behind it?
Special relativity
this is why I can't make a wirless charger
Does anyone know what program he uses to do this?
+darkgcn14 Read khanacademy FAQ
+darkgcn14 MSPaint
2:35 what were u thinking 😂
Gauss but with electromagnetism got it
Shouldn't the current be going anti-clockwise to begin.
Field is coming out the plane so right hand rule??
thats what i though. im confused.
It should be
Since the induced current creates an induced magnetic field
And this induced magnetic field should oppose the original increase in magnetic field strength
So it would make sense for the current to be travelling in an anticlockwise direction so as to have the induce magnetic field Vectors point in the opposite direction of the increase in magnetic field strength which was coming out of the screen
2019?
So basically, the more smooth the more current am I right ?
Magnetism and Electricity.
Those are electrons. Current is the flow of electrons
❤❤❤❤👏🏻👏🏻👏🏻👏🏻👏🏻
Whatever happened, happened. That’s Faraday’s law.
How does inducing an emf cause a current to be induced
Because electric and magnetic fields oppose each other, thereby creating an EMF. Well, I stated that backwards, but it's reciprocal.
An EMF causes a current to be induced
This is because EMF is Voltage
It is a potential difference
This potential difference within the wire induces a current
@@solcoster8110 lol I remember asking this when I was going to write my unit 1 sixth form exam. Thanks alot bro 🙌🏼
@@drainfish8019 No problem bro
My response was 3 years late so assuming your in college or University now
👍👍👍👍👍👍👍👍👍
k
M
why does "CHANGE" in magnetic flux induced a current?
I think it you're pushing the electrons around.
Project Hu148 the answe is in quantum physics not in classical physics
really good question, but no one here can actually anser it
The easiest you can expect
I'm writing tomorrow help
Sorry i dont get it
Current and magnetism are one and the same entity. Magnetism is the turbulence of moving electrostatic loss of potential. A good analogy is the helical vortex in water when an isolated current of water is moving with higher velocity relative to the surrounding water. This turbulence of water has both attractive pulling and repelling pushing properties just like magnetism does. It is a 100% accurate analogy because electrostatic field mechanics are hydrodynamic.
You need a bit more proper schooling before trying to teach anything about Faraday's law...
Arabic captions pls
i still do not understand it ☹
Why am I here am 15 and just wanted to know how microphones work....well I know now after like 1-2 hours of rabbit holing but I still shouldn't be here
This video made me hate the word 'change'
"chyaaaaange"
horrible explanation