Emf induced in a rotating rod (& disc) - Motional EMF | Electromagnetic induction | Khan Academy

Let's explore how to calculate the induced emf in a conducting rod rotating about its end in a uniform magnetic field.
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Created by Mahesh Shenoy

[@mayankdhounchak190]

huge efforts are being put by him, RESPECT FOR THIS GUY.

[@alphacuber5593]

Thank you for this. I haven't had anyone explain it to me this clearly. Great work.

[@vivekgupta3692]

Sir Please Solve My Doubt - Sir In This Arrangement We Can Clearly See That There Is No Change In Flux While Rod Is Rotating , But There Is An Induce EMF Only Because Of Motion Of Rod (Not Because Of Change In Flux) Is This Violation Of Faraday Law ?

[@riteshbhardwaj1681]

No .Faraday law is for coil .

[@KhanAcademyIndiaEnglish]

You are right about EMF induced without a changing flux. But Faraday never said you couldn't induce Emf without changing flux! All he said was changing flux would induce an EMF.

[@vishaljoy6802]

Dood this doubt was killing me thnx for answering!!!

[@smileyyyy7372]

I had the same doubt after watching video and then I was searching for any comment if anyone had asked this...Thanks !! its clear now😮

[@KrishAggarwalA]

@@KhanAcademyIndiaEnglish thanks bro that doubt was killing me for years now its clear

[@losethbandara2780]

Really appreciate the hard effort you given for this. This is much better thought than at class

[@freeverse4210]

Now I love science it's interesting when you are speaking each word feels like the console of God so smooth and so interesting thanks for making my life interesting through this teaching

[@kalaiselvanrajasekaran8352]

Sir please make a playlist for current electricity chapter based on the videos u have posted

[@sanasayma3260]

U truly deserve respect🙏 ...keep going sir.

[@shiwamkarn5215]

Omg amazing..this chapter is going on in my class..plz complete this as soon as you can with same effort..I really love it way..thank u so much

[@mebsoumya0684]

Ohhhoooo 13mins n u r ready to solve questions...thanx man❤️

[@SAURABHKUMAR-oy3nh]

Sir please Hindi mai bhi video banaya karo

[@VedantaDas]

He is mahesh sir❤ float head physics 😊😊😊

[@akshaypatra612]

Very intresting to learn😎 from you

[@sohamajumdar9677]

Is there a way we can send our doubts to you guys ? As image or something

[@justlearn3444]

Lots of love Sir please update the playlist

[@AbhiYadav-jy3ej]

Very very very good teacher❤❤❤❤❤

[@8pxl_]

best teacher on the subject period

[@KrishAggarwalA]

far better than my school

[@PavithranD22]

Can't we say that flux Is changing because of change in area vector direction while rotating?

[@HelloAayush]

Thanks bro. You cleared my doubt😊👍

[@speckinspace]

Cleared my concepts! Thank you so so much.

[@vanshmahajan9609]

God bless you ! What a wonderful video

[@whysoserious1150]

And where's the previous video??

[@aryan1389]

Khan academy always goes hard🤝

[@daylight1nsomniac536]

thank you for the explanation

[@sridharchitta7321]

Faraday’s law is very general and any change in magnetic flux, whether due to a change in magnetic field or, a change in area, produces an emf equal to the rate of change of flux. In fact, both may be present simultaneously, as when you drag a metal bar along metal rails with one end of the rails bridged by a resistor and there is a uniform magnetic field in the area between the rails and bar and resistor. Assume, the magnitude of the uniform magnetic field is increasing. The flux is BA, where B is the magnetic field and A the area enclosing it, and the rate of change of the flux is due in part to the change in the magnetic field, and in part to the change in the area enclosed by the changing path. The resistor will heat up! The equation of the rate of change of flux....without the details of the derivation are = (dB/dt) A + BLv (Change of B, fixed path) (Change of path) The calculation is a bit mysterious. Physically, where did the emf represented by BLv come from if it is not associated with a changing magnetic field? Befire we provide an answer, it would be instructive to understand Current, the conduction process and Voltage at the fundamental level. Electrostatics and circuits belong to one science not two as in the following two videos: i. kzbin.info/www/bejne/ioXXpWVul5aXj9E and ii. kzbin.info/www/bejne/bnO0fpKurJeFnNE Now, returning to the experiment of the moving bar on rails, we see that we have a conducting metal bar and we are moving it. Note carefully that we are moving the jumpy energetic conduction band electrons in it as well. As a result of the magnetic force (due to the presence of the uniform magnetic field), the free electron sea shifted, and the bar polarized and a Coulomb electric field develops and that is how an induced emf is produced. It is not possible in this post to discuss in more detail the process of polarization and the consequent production of an emf. The last frame References in video #1 lists textbooks 3 and 4 which discuss these topics in more detail using a unified approach and provide an intuitive understanding of the generation of an emf in generators and motors.

[@learn2observe540]

Sir plss give the link of motional emf video

[@namitapanda3092]

This is motional emf

[@lizmariajose9481]

Nice explanation Sir Thank you😊

[@chetnachaudhary2262]

Thanks ☺️

[@RadhaSharma-ts1xw]

Thank u soo much

[@kavinkishorex-bi9477]

I wish my phy teacher was this good.

[@Nataspin900]

thank you kind sir

[@tendi.rutsate]

Amazing

[@rudraphysics2646]

Good explanation

[@ar-rohoman2417]

U are great concept clearing mastar

[@Rohan-tj1dr]

Thank you very much ram bhaiya

[@anilsurjewala3606]

Lots of love

[@janmeshsamvlogs7917]

Great 👍 👌

[@studyroa9045]

thank you

[@asapacsin]

It does not seem to suit the law of conservation, the kinetic energy not going to decrease when the emf is induced.

[@rudra5662]

really Good 👍👍👍👍👍👍👍👍👍👍👍👍

[@PrabhjotSingh_24]

we haven't talked about motional emf in the previous videos sir

[@rajbardhansingh5051]

In second part of question where disk is discussed, How can multiple rods can be joined to form a disk.I think it will never form a disk rather it will form a rectangle.

[@aalerasul5382]

Hats off to you bro

[@om-physicsnmvs]

Thank you sir🙏

[@namitapanda3092]

Nice

[@IntelR]

Love your lectures ❤️

[@preetam714]

sir please make a video on cyclotron

[@tasneem6427]

It’s not in our 12th syllabus

[@angadsingh6478]

@@tasneem6427 only 2020 batch is exempted

[@whytho2030]

@@tasneem6427 still its pretty cool and important concept

[@whytho2030]

try Readin ncert

[@tasneem6427]

@@whytho2030 Yes you are right

[@shibaneethakur5035]

Why did you choose magnetic field into the plane....????

[@user-go2rc5jo9u]

For better explanation of motion

[@Mychannel-fm3vo]

U r really a legendary 🐐 goat

[@magicinphysics9829]

💗💗

[@janhviguptavlog_mirandahou2860]

Best 👍🤣🤣🤣👍🤣👍👍😊👍🤣👍🤣🤣👍😊

[@ayushijha9634]

How is flux changing in disc

[@guillaume6373]

Wow, great video :))

[@medico3989]

Sir how omega is constant 🙂

[@93katwal]

Because rod is moving with constant velocity

[@medico3989]

@@93katwal Thanks a lot bro❤️

[@atharvamayekar7085]

Why English accent??

[@Samridhi2410]

it's difficult for you to appreciate people no? hope you get better in life❤

[@atharvamayekar7085]

Neither I am depreciating,just asked a question you should Google the meanings of the words before you use it. Hope you get better in life ❤️🙌

[@unnatii777]

Why are forcefully trying to speak western when it sounds nothing like that