H.C. Verma is wrong!

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FloatHeadPhysics

FloatHeadPhysics

Жыл бұрын

The expression for Drift velocity derived in the book 'Concepts of Physics 2' by HC Verma has a subtle error!
Resource:
www.feynmanlectures.caltech.e...
Check 43-3 'The drift speed' section
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Пікірлер: 264
@vattevineeth4567
@vattevineeth4567 6 ай бұрын
Back in 2011 when I was preparing for my JEE, I followed HCV for physics and tried to derive every equation myself by understanding the concept. My derivation did not give me a 2 in the denominator and I tried discussing it with my lecturer. Sadly, they were all focused only on formulae that mattered in exams and didn't want to discuss it. Now I feel relieved that I was thinking along proper lines and can mark the highlighted doubt as closed (if I ever open my HCV book again)! Thank you
@shihab3611
@shihab3611 6 ай бұрын
I am preparing for JEE as well and coincidentally even I am experiencing this same thing. Every teachers are purely focused on syllabus and not the reason for studying.
@koushikkumarghosh5887
@koushikkumarghosh5887 6 ай бұрын
​@@shihab3611Exactly
@ShanBojack
@ShanBojack 5 ай бұрын
​@@shihab3611these days it's all about solving mcqs
@shu.c
@shu.c 4 ай бұрын
Same here also
@joshstudios240
@joshstudios240 3 ай бұрын
its a shame on the teacher for not doing the correct thing and just do what evere their books says. The eacher must have a reason of everything while deriving any equaton or expression in Physics.
@aryanraj441
@aryanraj441 Жыл бұрын
I like how you force more on the intuition part rather than pen and paper proof , it at the end just starts to make sense.
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Trying to gain and share intuition is what I try to do 90% of the time! It's super fun!
@_Future_IITian
@_Future_IITian Жыл бұрын
Sir I have a doubt At 9:14 it's an avg time that mean most of electron collide exactly at 6 min not before it is'nt it. Therefore if we apply 2nd eq of motion for all electrons then it shouldn't be wrong, right?
@robertoatmac
@robertoatmac Ай бұрын
question arises whether it is drift velocity of single or an average d, velocity? isnt it?
@varunarora1256
@varunarora1256 11 ай бұрын
Really got a deep understanding after seeing this, rather listening to this, the intuition. Had to repeat watching this 2-3 times to understand better. Thanks and please keep doing what you're doing 'cause many people aren't doing science the way it was and is meant to be.
@rishavmukherjee2093
@rishavmukherjee2093 4 ай бұрын
Can you solve it rigorously that how did you get that 2t term as in chat gpt i got the result that if t1 is not equals to t2 and so on then there's no direct proof
@NaseerAhmad-dd6pp
@NaseerAhmad-dd6pp 6 ай бұрын
Can u tell me the page number and volume of concept of physics HC Verma
@bobinkurian3357
@bobinkurian3357 3 ай бұрын
Maybe there is a statistical solution to the problem which gets the numerator to be twice that of denominator, leading to the removal of 1/2.
@BarcaFanaticOfficial
@BarcaFanaticOfficial 6 ай бұрын
can you link a proof for 18:20 ? I tried to find it online, didn't find it
@AkashYadav-br9sm
@AkashYadav-br9sm 9 ай бұрын
If u want to be so specific then u should also introduce some resistivity becoz different materials have different drift velocity due to different no. and type of collisions and the resistivity they offer.
@vik24oct1991
@vik24oct1991 11 ай бұрын
The factor of 2 comes from rms time over mean time, as we know rms time is sqrt(2) times average time for sinsoidal curves hence the rms^2 is 2 times greater but for that we need to assume that distribution of the collision is a sinusoidal curve which might come from quantum wave function of electron in a substance, hence feynman probably got it right as he worked on field of quantum electrodynamics.
@anuragsharma4452
@anuragsharma4452 9 ай бұрын
What if we start with v=u+at and for each collision find out v and then average out v. then average v= [(u1+u2+.......) + a(t1+t2+......)]/N (Here, N represents the no of collisions considered) average v = 0 + a tau= a tau = ( e E / m) tau
@gigastein3151
@gigastein3151 Жыл бұрын
Sir there was a question of kinematics earlier of three particles on the corner of equilateral triangle. Sir you had done that question using relative motion but I want to know other ways to do that question too. Please If you can reupload and show us other ways to do that problem that would be very beneficial for me. Thankyou.
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Sure, will add it to the list!
@gigastein3151
@gigastein3151 Жыл бұрын
@@Mahesh_Shenoy Thankyou sir
@m.venkadesen9037
@m.venkadesen9037 Жыл бұрын
Mahesh sir because of u i got 94 in physics in my board exam tq
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Hey, that's so great to hear! Also, correction! You got 94 because of YOU!
@user-pj1wv1ns9x
@user-pj1wv1ns9x Жыл бұрын
Class 12 boards? But is every topic covered at Khan academy
@aditya_asundi
@aditya_asundi 7 ай бұрын
Yep it is@@user-pj1wv1ns9x
@anonymousanon420
@anonymousanon420 Жыл бұрын
I liked your videos on khan academy india but they haven't been arranged in a playlist so I don't know which one to watch after the first 4 videos of this topic(current electricity). Neither on the site nor in youtube playlists. Going back to HCV for now 😅
@ramachandran453
@ramachandran453 17 күн бұрын
Since collisions are random as they are taking place in uniform force field. One can assume that time interval between successive collision is same and it is considered to be the relaxation time.
@aadiprasad3167
@aadiprasad3167 Жыл бұрын
I'd be quite interested in knowing how the term you obtained (in place of tau) could be proven to be equal to twice the average time. Any hints, please?
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
I am still shaky on that :-/
@rounitkamal2832
@rounitkamal2832 Жыл бұрын
Same question
@aadiprasad3167
@aadiprasad3167 Жыл бұрын
@@Mahesh_Shenoy Ah, never mind. I'll think about it, too. Please do make a video if you do figure it out please
@physicorum7107
@physicorum7107 Жыл бұрын
@@aadiprasad3167 did you find it out ?
@aadiprasad3167
@aadiprasad3167 Жыл бұрын
@@physicorum7107 I didn't think a lot about it to be honest 😅
@Nyo27
@Nyo27 5 ай бұрын
Sir why are we applying the equations of motion here? I mean how are we sure of the fact that acceleration of particles is constant, like if we try to delve deeper into this problem can't we say that the electron, as it moves through the conductor would experience a number of different forces like repulsive force due to other electrons and attractive forces due to positive kernels and in the interval between the collision shouldn't these forces vary?
@NB-sr2zt
@NB-sr2zt 4 ай бұрын
All the forces that you mentioned will be present definitely but the net effect of those forces will be zero on the drift distance similar to the 'ut' part he neglected during the derivation.
@abhishankpaul
@abhishankpaul 4 ай бұрын
This is an idealized model. If you plan to count every constraints and tiny factors then you won't be getting anything out of science
@saurav-zw3lh
@saurav-zw3lh 4 күн бұрын
I observed many did the average of final velocity before next collision to actually derive drift velocity . so how can we relate it llike I didnt get it
@technicallittlemaster8793
@technicallittlemaster8793 4 ай бұрын
I had the same issues with this derivation back in 2021. But yeah now I know. Thanks a lot.
@beegyyoshi
@beegyyoshi 5 ай бұрын
I think I am still confused about something, Comparing the derivations in both cases, The feynman lectures assumed the following - "It is just the acceleration F/m (where m is the mass of the S-molecule) times the average time since the last collision. Now the average time since the last collision must be the same as the average time until the next collision, which we have called τ" The fenman lectures said this before that line about τ - "If we start to observe an S-molecule at some instant we may expect that it is somewhere between two collisions. In addition to the velocity it was left with after its last collision it is picking up some velocity component due to the force F. In a short time (on the average, in a time τ) it will experience a collision and start out on a new piece of its trajectory. It will have a new starting velocity, but the same acceleration from F." Meanwhile for Hc verma the τ is defined as - " If τ be the averge time between successive collisions" I feel like in Feynman's definition the τ represents that if you are looking at a particle at a given instance, the avg time until the next collision and the time since the last collision is τ. The highest probility will be that you are looking at the particle when it right between the the past and the next collision. if you look at it like that, then the time between successive collisions will be 2τ, now if you take this value and plug it through hc verma's derivation(which assumed τ to be the time b/w successive collisions), you get L = (1/2)(F/m)(2τ)^2, for the drift velocity, you divide L by 2τ and you get v = (1/2)(F/m)(2τ) = Fτ/m. I think the problem lies in the assumtions sorrounding what τ represents, one assumes that it is the avg time until the next collision and time since the past collision, meanwhile the other assumes it as the time b/w 2 collisions, this why hc verma has a 1/2 in the value, hence his τ(time b/w succesive collisions) becomes τ/2 which then represents the time since the last collision and till the next collision.
@thechimeraretribution1588
@thechimeraretribution1588 5 ай бұрын
Hi Mahesh. The part where you have made sigma( u t ) = 0 Can we also not say that each new ut also contains the memory of previous acceleration v = u + at Also the summation of t squares looks like can be done using rms value calculations
@Uncle_johanxrz
@Uncle_johanxrz 3 ай бұрын
No since the after collision the initial velocity will be zero or at the exact moment it will be in resting position
@sachleensingh56
@sachleensingh56 10 сағат бұрын
Did Resnick Halliday made the same mistake? As Prof. Verma often mentions he referred Resnick Halliday before writing Concepts of Physics
@mridulacharya8250
@mridulacharya8250 Жыл бұрын
Can U please make a video Schrodinger wave eqn to explain it to 11th standard students...I mean it's there in the syllabus (Idk why they want to add as much syllabus as they can and don't give us time to allow to even think properly)...it's been many days I have been stucked in that topic..I don't understand what does this eqn tell us...does it tell probability?does it tell energy??does it tell momentum??does it tell the shape of orbital??does it tell the size of orbital?does it tell the orientation of orbital??.
@jeeaspirant9252
@jeeaspirant9252 Жыл бұрын
Schrodinger himself couldn't explain it.
@mridulacharya8250
@mridulacharya8250 Жыл бұрын
@@jeeaspirant9252 Max born did it!!And m not asking what does the wavefunctn mean...I am asking what does it gives us...bcs based upon that only we predicted shape of orbital...energy of e etc.
@livingbeing8661
@livingbeing8661 Жыл бұрын
@@mridulacharya8250 the equation is very complex to understand at a first glance but to put it in easy words it tells us about the energy, like both potential and kinetic energy of an particle. It gives us the idea to where a particle is most likely to be, the probability of the particle location. It is a function like any other and varies over time. So to conclude it'll tell you everything about a particle depending on time. Hope it helps and I would suggest you to read online articles if u want to know more
@mridulacharya8250
@mridulacharya8250 Жыл бұрын
@@livingbeing8661 Ooo.. Btw I read many
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Not an expert on quantun whatever! Would you folks be okay if I made videos on topics that I do have some perspective to share but am still shaky on?
@ritishkumar4711
@ritishkumar4711 5 ай бұрын
I derived the equation in slightly different way and I got result without that 2 in the denominator.. That's what I have been teaching to my students.. If you provide your email so that I can send you the derivation to check by yourself, whether it is right or wrong? By the way it was nice explanatory video.
@SayanMitraepicstuff
@SayanMitraepicstuff Ай бұрын
I too realized the discrepancy while I was preparing for JEE. I followed the physics book by DC Pandey where the correct derivation was there and also a comment on how some books derive the equation with a factor of half. Although theoretically not having the half made more sense to me, I believe there is no real way (not inferred from this formula*) to measure the relaxation time for electrons.
@padraiggluck2980
@padraiggluck2980 Ай бұрын
But there is a mean free distance between collisions that depends on the density of the conductor.
@morgoth8815
@morgoth8815 Жыл бұрын
I was searching for a video on drift video derivation, I had a test next week and I suddenly remembered this video(I had seen this video for timepass and due to the thumbnail, I had not studied Electric current yet)
@MiteshJethawa
@MiteshJethawa 5 күн бұрын
Same Ngl Checking Again After our Sir Told Us To Read The Derivation From HCV
@samarjyoti-ray
@samarjyoti-ray Жыл бұрын
Such a coincidence, I was studying this an hour back!
@____.a.y.u.s.h._
@____.a.y.u.s.h._ Жыл бұрын
Same bro :-)
@sagnikghosal8276
@sagnikghosal8276 Жыл бұрын
Same
@Dk-kf6dg
@Dk-kf6dg Жыл бұрын
Same
@TheChaosChannel.
@TheChaosChannel. Жыл бұрын
I just revised this chapter few minutes ago
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Wow!
@user-im7tb9tq5d
@user-im7tb9tq5d Жыл бұрын
I don't know much but the 1st problem you raised is insignificant as by taking the average time we are also considering the average distance. Therefore, the ratio ultimately remains almost the same with some negligible error (probably). I might be wrong. I am just in class 12. Sorry for the inconvenience caused.
@thefinalsceneismissinggrea6172
@thefinalsceneismissinggrea6172 Жыл бұрын
Yes you are correct brother
@atifr5001
@atifr5001 Жыл бұрын
in HC Verma's book note that he is squaring the average time instead of taking the average of time squared. with these simple and similar assumptions, we do not get one result that is half of the other when they are supposed to be equal [v=d/t = (ut+1/2at^2)/t]
@rajneeshtetarwal8654
@rajneeshtetarwal8654 Жыл бұрын
well if you are dealing with this problem in this quantum state, then you can't take the acceleration due to electric field common for all the motions , you will have to take the components of acceleration along the direction of motion to use it in the newton's equation as you did at 11:22 ,so its better to solve it larger dimentions as in hcv
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Acceleration will be a constant since the electric field is uniform!
@rajneeshtetarwal8654
@rajneeshtetarwal8654 Жыл бұрын
@@Mahesh_Shenoy but the electric field is uniform in a specific direction and is in a single direction through the motion ... but here the same acceleration is used for motion of the electrons irrespective of their direction of motion not being along the net acceleration...... i might be wrong regarding this as i am not as confident as you in this topic ....but according to our class 11 kinematics for calculating the displacement along the motion we consider the component of net acceleration along that motion .....
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
@@rajneeshtetarwal8654 Oh, yes I should have used the vector signs! I always forget to do that!! The vectors signs take care of them!
@anshulgarg3758
@anshulgarg3758 Жыл бұрын
​@@Mahesh_Shenoy kzfaq.info/get/bejne/oKt7iNKYm5OwmXU.html what hc verma says
@ScientiaMinds
@ScientiaMinds 9 күн бұрын
15:18 the assumption "time gap between collision is equal" is mentioned in his book. And based on the the assumption he is quite correct, but yeah the assumption goes very far way from the actual values.
@user-nobody_
@user-nobody_ Жыл бұрын
DC Pandey has also teased about this in his Understanding Physics series, just read it yesterday 😅
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Oh really? I didn't know that! Is there something online that you could share?
@vinodhc5239
@vinodhc5239 Жыл бұрын
Hi makesh sir plz write physics textbook for class 11 and class 12 Surely ur book will be next halliday and Resnick book
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Aww shucks, that's such a compliment!
@pranavpriy8108
@pranavpriy8108 Жыл бұрын
I ask this dout when i m in current electricity but that time i did not get the satisfactory answer but now i am quite clear about it🙏
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Glad to hear that. (The second part, not the first)
@KD-onegaishimasu
@KD-onegaishimasu 4 ай бұрын
i cannot speak to the physics, but i can confirm your statistics are perfect: the only way to make Σt²/Σt come out Verma's way is if the variance of t is 0. that's not just sufficient but also necessary
@paulg444
@paulg444 Ай бұрын
i would love to see the QM derivation of the Sommerfeld model. The problem is really that the classical physics is insufficient and the best we can do classically is to first establish the simple instantaneous velocity function as being qE/me times t . Now we can take the Expectation (averaging) but we have to then employ a "mean free path time". But this is problematic in QM and of course one needs to account for the fact that Expectations under any distribution obey: E[t^2]= E[t]^2 + var[t]. Getting the distribution right is where the real work s and this is why Sommerfeld makes the proper correction over the original Drude model.
@hell.of.lucifer
@hell.of.lucifer Жыл бұрын
Rajwant sir of pw also pointed out same think
@sarbajitdutta5193
@sarbajitdutta5193 5 ай бұрын
Hi Mahesh! Wonderful video again. I think none of them are 'wrong' per se. Actually, the motion of electrons in a material is a very complex quantum mechanical problem. We have to come up with approximations in order to predict experimentally measurable quantities (like conductivity for example). H.C. Verma chooses a lesser sophisticated model for his calculation, and the one chosen by Feynman (Drude Model) is the just a more sophisticated model. But both of them are still models. They are simplications of the quantum mechanical problem using equations from classical physics. Now, the 'test' for a model is how well it can explain an experiment. As far as I know, people only roughly measure the order of magnitude in case of drift velocities, and for metals both the models work well. Both of them fail in case of other materials. Nevertheless, Feynman's model is indeed more sophisticated and has a subtle catch like you mentioned, which people usually miss. Thanks for making this video!
@Mahesh_Shenoy
@Mahesh_Shenoy 5 ай бұрын
Thanks for sharing, Sarbajit. Are you the same Sarbajit that I know? :D Surely, we are approximating things. But, H.C. Verma has made a fundamental error in the math. They are both the same models with the same underlying assumption - electrons are tiny balls that bounce of elastically.
@sarbajitdutta5193
@sarbajitdutta5193 5 ай бұрын
Hey again! Yeah, I'm the same Sarbajit xD Well, yeah both do the same assumption in considering electrons as elastic balls. But don't you think there's another level of approximation over it? HCV assumes that each electron is travelling with the same velocity in the same time. On the other hand, Feynman assumes a distribution, i.e, velocities can be random which requires an average that he does later like you said. Now, of course there's no reason to assume what HCV did, so that's why I might call it a less sophisticated approximation.
@Mahesh_Shenoy
@Mahesh_Shenoy 5 ай бұрын
@@sarbajitdutta5193 good to hear from you, bud! Whether you approximate all electrons to travel with the same velocity or not doesn’t matter :D it should yield the same result. Because, in this model, we assume the electron randomised after each collision. So, a single electron over a billion collisions or a billion electrons over a billion collisions should yield the same result.
@lovewithcode7914
@lovewithcode7914 5 ай бұрын
​@@sarbajitdutta5193accept wrong as wrong.. we human still consider those both model Valid because we are Faliure cannot prove one fully wrong... But Drude model is more correct than HCV sir assumption
@sarbajitdutta5193
@sarbajitdutta5193 4 ай бұрын
@@Mahesh_Shenoy Well yeah. It is still the hard sphere approximation. However, doesn't HCV make an additional call by making all the electrons do exactly the same thing so that the motion of one electron is equivalent to the average motion? Probably, I'm not being able to put it in a nice way. I'm sure there is a better way to put out my point :')
@roughero1353
@roughero1353 Жыл бұрын
Ok we need more of these for all concepts in HCV
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
I didn't find any major errors besides this! Did you?
@roughero1353
@roughero1353 Жыл бұрын
@@Mahesh_Shenoy We knew during our preparation that this was wrong but the explanation here is gold so I would really like to watch more of your explanation for different concepts that are there in HCV right or wrong doesn't matter just the thought behind it like you presented here
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
@@roughero1353 Oh man, that's really encouraging!!
@ankitthakurankit4764
@ankitthakurankit4764 Жыл бұрын
he has already made ideo on that actually what happens is that all these physicist try to model those quantum phenomens into very suffocative mathematics thats why these problems arises actually all these are just mere approximation of that quntum phenomenon.
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
In that video, he mentioned that the discrepancy was because of the difference in assumptions. But the point is, under the assumptions made by the professor, the derivation still has errors!
@sudiptabasu96
@sudiptabasu96 Жыл бұрын
@@Mahesh_Shenoy Excellent work and please keep up the good work. The problem is that a large cross-section of world population continues to live with tribal mindset and herds mentality even today. And we human beings are not to be blamed for this - indeed we lived the life of herdsmen and tribes million years back. This gives rise to cult following. Once somebody becomes a CULT - he becomes a GOD - other members of the tribe won't allow you to question that CULT - that's why you get to Jaggi Vasudev, Ramdev etc. Two years back I got into an argument with some kids over a KZfaq video by H.C. Verma - question was regarding the magnetic effect of a moving charge. I found H. C. Verma's explanation rather naive and incomplete and I have seen many such flaws (of Prof Verma) before. I commented that Prof Verma loves Physics and probably wants to learn Physics, but he is NOT an expert. This irked some kids - some of them appeared and probably about to appear at IIT JEE. They immediately started to throw their weight around by flaunting their IIT JEE ranks and all - which of course I won't cross-verify. I off course won't throw my weight around saying I completed my B.Tech in so and so year - did my Masters in so and so year - happened to work in so and so Semiconductor MNC Majors in so and so places and in so and so positions and took part in so and so R&D projects and that my son is a student at so and so IIT at that point in time. Honestly, when I wrote IIT in 1998 paper pattern was 40 X 2 + 15 X 8 in three hours - my son thinks it was tougher then paper-wise may not be competition wise. And anyway, an IIT rank itself isn't a testimony of one's understanding of Physics. I just tried to be humble. But finally I had to say that Prof Verma is more of a HYPE and a CULT. And it is extremely difficult to convince others that CULT-FOLLOWING isn't a good idea.
@ankitthakurankit4764
@ankitthakurankit4764 Жыл бұрын
@@sudiptabasu96 relax brother don't hurt your sentiments this comment was just to give a notice or an information to our sir that he had already made a video on that maybe he could have missed that and if you are talking about prof. Hc verma being an expert then i would say no one is and no one was prof. Hc verma is a great teacher and you can't deny to that as teaching is a skill it is not necessary that a good teacher should be a good exlert as well for example take alakh pandey he is no expert of the subject physics but he is a good teacher . Now the point of being perfect is useless because one of the greatest minds of time like sir albert Einstein, issac newton, even sir richard feynman were not always correct they all have made errors at various points of their life einstien assumed space to be constant that isn't the case newtons laws doesnt holds good in extreme conditions niether does that give a great qualitative analysis and about sir fenyman people regard him as the man who didn't understand his own theories . But does this mean they were all dumb ?! No ! They were one of the genius minds we had in their fields similarily hc verma is not regarded as a great physicist but as a good teacher . I think you were somewhat hurt at some other things and this comment became a medium for you to remove the rage but i think you shouldn't be using words like cult or herdism for teachers and the disciples because a teacher is just a torch who is gonna enlight the way but enlightenment is what you'll get yourself only . Like arjuna he took basics from his guru dronacharya but didn't confined himself to that only he became versetile never stopped learning and was regarded as the greatest archer . But dronacharya wasn't hope you got the point. No impudence intended.
@atifr5001
@atifr5001 Жыл бұрын
All of what you said makes complete sense mathematically. When we average some values, we think that 'this average would be the value if all quantities were to be equal'. So HC Verma has taken an average value to calculate the distance an electron would travel if collision times were equal. Is not what Feynman doing too in his book by saying V=a*𝜏 (where 𝜏 is the value of avg. time we'd get if all times were equal)? The logic is same and i thought about it the same way as both seemed equally correct. I thought maybe Newtonian mechanics break when dealing with electrons but no! because we assumed electron to be a particle. I also thought that both equations of motion connect then the derived formula for Vd must connect mathematically but they do not. { if d/t = (ut + 1/2 at^2)/t then how 1 result is half of the other- i wonder how a physicist did not think about this) Now that i think, it makes sense - how did he average out (ut) but not the square of t instead averaged out t first then squared it. According to my observation, all of the problem lies in not using the simplest forms for the physical quantities we are referring to (for example 𝜏) Is it because symbols are just used for short notations and while explaining mathematically we must refer to the simplest form and most original definition of formulas and physical quantities we are using? I am a newbie at Physics and go introduced to real Physics only by you Mahesh, so i am just thinking. I saw your comment in Verma's video and discovered that you have a channel too. Hope you read this.
@madurangan1477
@madurangan1477 Жыл бұрын
isn't the path between successive collisions parabolic?
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Yes it is!
@quantum120
@quantum120 5 ай бұрын
With arbitrary collision statistics, the general drift velocity is proportional to E(T^2)/E(T), where T is the random variable denoting the time between successive collisions. This follows from a simple application of the Strong Law of Large Numbers. This quantity is at least E(T) thanks to Jensen's inequality. Now, assuming T is exponentially distributed with mean t, this works out to be 2t.
@italkcode
@italkcode Жыл бұрын
Shouldn't quantum mechanics instead of newtonian mechanics be used? Moreover the length of path travelled by electron would be uncertain... due to hiesenbergs uncertainity , it would be impossible to accurately determine the position of the electron?
@abhishankpaul
@abhishankpaul 4 ай бұрын
This is why we are using statistical approach
@monke4216
@monke4216 Жыл бұрын
12:44 all the electrons can drift automatically . But what if half of them drift the other way ? Then the current would be zero right? 👀
@aadiprasad3167
@aadiprasad3167 Жыл бұрын
Isn't that why there's no current without potential difference?
@monke4216
@monke4216 Жыл бұрын
he said "all the electrons can drift automatically so we get a current " so why does he assume that all the electrons drift the same way ?
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
@@monke4216 If half can drift the other way, half the collisions should also make the electron displace in the opposite direction giving net displacement zero. Remember, a billion electrons moving randomly within a single collision = the motion of a single electron over a billion collisions.
@aadiprasad3167
@aadiprasad3167 Жыл бұрын
@@Mahesh_Shenoy It still comes down to net displacement = 0 implies current = 0, no?
@amittksingh
@amittksingh 4 ай бұрын
Hi Mahesh, You are a talented teacher. But so is HC verma sir. He has brought a revolution in making physics accessible to school level children in an intuitive way. Seeing a big red cross sign on HC verma sir's photo in your video is little hurtful and disrespectful. You can make a point with words and content. Talented folks like yourself talk about ideas not people. Wishing you good luck!
@nybble
@nybble 8 ай бұрын
I'm a year late to this video! Professor Walter Lewin in his 8.02x - Lect 9 video derives the drift velocity assuming a constant average time between collisions and arrives at (eE/m)t without the 1/2. It's the first few minutes of this video - kzfaq.info/get/bejne/hrChgsR5p83WY2Q.html
@parthbhardwaj1807
@parthbhardwaj1807 Жыл бұрын
I asked this discrepancy between hcv and Resnick to my teacher. He told me that actually both of them are wrong and don't agree experimentally. But for jee domain we take the Resnick formula.
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Next time your teacher 'claims' something like that, ask them for more details. For example - What was the experiment? What did they find experimentally? Where exactly is the derivation wrong?. And most importantly, what's their source of this knowledge?
@parthbhardwaj1807
@parthbhardwaj1807 Жыл бұрын
@@Mahesh_Shenoy he told me that it is much more complicated experimentally. He has master's degree in electrical engineering so probably would not be saying made up things. As for the derivation part,maybe the model of electron hitting and then randomly restarting itself is a crude approximation. Or maybe classical mechanics is insufficient at that level
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
@@parthbhardwaj1807, I have seen folks carrying a PhD and not really understanding Newton's laws! I don't trust Indian degrees!
@sudiptabasu96
@sudiptabasu96 Жыл бұрын
@@Mahesh_Shenoy Excellent work and please keep up the good work. The problem is that a large cross-section of world population continues to live with tribal mindset and herds mentality even today. And we human beings are not to be blamed for this - indeed we lived the life of herdsmen and tribes million years back. This gives rise to cult following. Once somebody becomes a CULT - he becomes a GOD - other members of the tribe won't allow you to question that CULT - that's why you get to Jaggi Vasudev, Ramdev etc. Two years back I got into an argument with some kids over a KZfaq video by H.C. Verma - question was regarding the magnetic effect of a moving charge. I found H. C. Verma's explanation rather naive and incomplete and I have seen many such flaws (of Prof Verma) before. I commented that Prof Verma loves Physics and probably wants to learn Physics, but he is NOT an expert. This irked some kids - some of them appeared and probably about to appear at IIT JEE. They immediately started to throw their weight around by flaunting their IIT JEE ranks and all - which of course I won't cross-verify. I off course won't throw my weight around saying I completed my B.Tech in so and so year - did my Masters in so and so year - happened to work in so and so Semiconductor MNC Majors in so and so places and in so and so positions and took part in so and so R&D projects and that my son is a student at so and so IIT at that point in time. Honestly, when I wrote IIT in 1998 paper pattern was 40 X 2 + 15 X 8 in three hours - my son thinks it was tougher then paper-wise may not be competition wise. And anyway, an IIT rank itself isn't a testimony of one's understanding of Physics. I just tried to be humble. But finally I had to say that Prof Verma is more of a HYPE and a CULT. And it is extremely difficult to convince others that CULT-FOLLOWING isn't a good idea.
@ankitthakurankit4764
@ankitthakurankit4764 Жыл бұрын
And i thought rechard feynman himslelf came in the comment section😅
@sanjeevsinghrajput5593
@sanjeevsinghrajput5593 Жыл бұрын
I think, he uses the equation of motion, s = ut + 1/2 at² Even if we assume that he's correct by saying that sum of all u will become 0, but in such case, we will find S rather V (v is drift velocity while S would be displacement) In order to find the correct formula using the formula HC verma derived, we just keed to differentiate both side with respect to time S = 1/2 a × t² dS/dt = 1/2 a × d(t²)/dt V = 1/2 a × 2t = a × t Then we can replace a by eE/m
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
That gives you instantaneous velocity after time t since the last collision, and not the average velocity! :)
@sanjeevsinghrajput5593
@sanjeevsinghrajput5593 Жыл бұрын
@@Mahesh_Shenoy oh true, completely forgot about that Well I haven't ever used HC Verma, the other books I read, have the formula derived using V = U + AT, so the sum of all u becomes 0 and sum of all T becomes Tau
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
@@sanjeevsinghrajput5593 Yes, but there is a subtle result overlooked! NCERT, surprisingly, has done a really good job at it.
@ruturajborse874
@ruturajborse874 Жыл бұрын
@@Mahesh_Shenoy surprisingly
@joshuathomas9862
@joshuathomas9862 3 ай бұрын
a great teacher knows how to teach you well, but a legendary teacher knows where you can mistakes
@fahimabrar8141
@fahimabrar8141 6 ай бұрын
First time watching your video! Very intuitive! Thank you
@MaheshKumar-lx1ku
@MaheshKumar-lx1ku 6 ай бұрын
I think in Richard feynman's book the velocity is of that instant when electron is just collidies with the next electron and in sir hc verma's book he has taken the avg velocity of the electron after colliding.( please correct me if i am wrong )❤
@muhammadfaiz2586
@muhammadfaiz2586 Жыл бұрын
Duh so... What should I do if a question comes from drift velocity in Jee Advanced.....
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Use the NCERT formula!
@mayankgoyal35
@mayankgoyal35 Ай бұрын
If we take infinite electrons at a single time and find drift velocity We get average final velocity of these infinite electrons as eEt/m but this average final velocity. Of we want to find out the drift velocity (which is the average velocity during the whole free path To find that we have to find average of inital average velocity and final average velocity. Means that drift velocity will be equal to (initial average velocity + final average velocity )/2 = (0 + eEt/m)/ 2 So the correct drift velocity will be eEt/2m
@morgoth8815
@morgoth8815 Жыл бұрын
just realized you're the voice behind Indian SyllabusKhan academy videos.
@mridulacharya8250
@mridulacharya8250 Жыл бұрын
When we drop something from height h and we r asked about it's velocity *just before hitting the ground* we get it by eqn of motion....but in the eqn of motion we put distance as *h* and then we get the final velocity.... technically isn't the answer that we r getting telling us the final velocity after it has covered a distance *h*??But once it has covered h the velocity is 0?? But still the answer that we get is non zero..how??
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Excellent question! Imagine just before hitting the ground = h (meter)- 1 (nanometer). Now plug in and see what you get!
@mridulacharya8250
@mridulacharya8250 Жыл бұрын
@@Mahesh_Shenoy Same value(non zero) So velocity after covering h distance(0m/s) is not same as velocity after covering h-1 distance(the non zero value) But it doesn't matter if we put h value or h-1 value it's gonna give us the same value...what??Physically we know the velocities won't be same but mathematically they r same??:(
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
@@mridulacharya8250 That's because, in your equation, you aren't considering the acceleration due to force from the ground! If you did, you will start to see deceleration after h, and it would eventually stop after h+ something!
@mridulacharya8250
@mridulacharya8250 Жыл бұрын
@@Mahesh_Shenoy Ooo yeah the eqn doesn't know it hits ground after h...so even if I put value more than H it will give me some bigger non zero value than before(because it just tells the velocity after a point of time as if the motion is continued without any disruption like force from ground...so U put time and get velocity assuming the motion is not interuppted)...Cool!!
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
@@mridulacharya8250 Yes! Don't every stop asking questions!
@projester136
@projester136 Жыл бұрын
u1t1 u2t2..might not add up to 0. Since the motion is not biased we cant have any biased initial velocity (from the point an elecyron strikes a lattice) so u1+u2+...un should be 0..not their sort of weighted timed mean.
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Interesting. My take is that the displacement of an electron, in the absence of any field, over a billion collisions should be zero, because there is no current! What do you think is wrong with that process?
@nhk0619
@nhk0619 Жыл бұрын
Your words are not clear enough. Tell nicely
@vik24oct1991
@vik24oct1991 11 ай бұрын
@@Mahesh_Shenoy It tends to zero, you can never say it would be exactly zero, but it would be negligible compared to the velocity when electric field is applied, and assuming that current is zero in absence of external electric field is also not completely accurate, it is zero on average as fields cancel out overall but at some places there are non zero fields which are the reason for van der waal forces but expected value is over infinite trials so even in this case though its over billion collisions there will be slight drift velocity but it will be close to zero.
@bealonexrrk
@bealonexrrk 14 күн бұрын
​@@Mahesh_ShenoyAs you are saying that there is no current. Is that current from a single electron or billions of electrons? If it was because of a single electron then the displacement must be zero But if it was because of billions of electrons then you can't simply take the displacement of a single electron zero . You can also think about it in this way like after billions of collisions how much possibility is there for a single electron to come in the same position where it started its motion ?
@bulletinskull001
@bulletinskull001 Ай бұрын
i think (v= u + at) is taken here finally after derivation (t= avg time for all collisions)
@sgiri2012
@sgiri2012 Жыл бұрын
Can you please upload videos on electromagnetic waves topic? I have a exam next week. Please help me sir
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Oh, all the best :)
@ankitthakurankit4764
@ankitthakurankit4764 10 ай бұрын
11:59 sir i see an issue here in my understanding would you please elaborate. Here you assume that a single electron has a zero net displacement without a potential difference introduced. First of all you say there are billions of electrons and they are identical spheres according to you then first of all how are you able to say that net displacement of one of that identical sphere in a long time t is zero ? Please elaborate sir how are you able to figure that out from that havoc of billions of identical charges
@saurav-zw3lh
@saurav-zw3lh 4 күн бұрын
without electric field the net displacement of an electron is zero cuz there is no current by thermal energy but when potential is introduced it drifts
@physicsbhakt7571
@physicsbhakt7571 3 ай бұрын
No Mahesh your argument is totally fine. ProfHC Verma can also make mistakes he is a human I also found some errors in his book The problem is for over many years no one tried to correct it
@subadip777
@subadip777 4 ай бұрын
umm.. can't it be done using the equation v = u + at... v being the average drift speed and u will result up to zero due to randomness... and then all those t1,t2,...tn divided by n will give tau? I was taught this while doing this chp...
@masterod_student8663
@masterod_student8663 4 ай бұрын
yea thankfully our teacher explained this to us, and he told us that its not 1/2
@anirudhgoyal5603
@anirudhgoyal5603 Жыл бұрын
so which formula do i use for jee
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
The NCERT one!
@anirudhgoyal5603
@anirudhgoyal5603 Жыл бұрын
@@Mahesh_Shenoy got it sir
@nothingspecial9370
@nothingspecial9370 Жыл бұрын
Omg i was with the same question.. finally
@dr.neetakapoor8975
@dr.neetakapoor8975 10 ай бұрын
I have a doubt that In your solution as you have calculated the desplacement vectors separately And then added all up But wait!!! As the angel between all the vectors is not 180° You can not add the magnetudes to get the net despacement vector For doing your calculations we should also have the angle between tho disspacement vectors
@shawon265
@shawon265 7 ай бұрын
I think there's a tiny mistake in your derivation ('mistake' might be a bit harsh tho). L₁, L₂ etc. are not the distance traveled in t₁, t₂ etc. Rather they are the displacements along the direction of electric field.
@wxua5859
@wxua5859 Жыл бұрын
I studied the same topic 5 minutes ago and just opened KZfaq to see this recommended lol
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Haha! YT is scary
@ishaanjdishaanjd7642
@ishaanjdishaanjd7642 25 күн бұрын
Because the drift velocity is considered not abs velocity instead
@user-ud3zt3ft6k
@user-ud3zt3ft6k Ай бұрын
In classical mechanics the half. Would occur but it doesn't. Occur in quantum mechanics
@namitkamani4732
@namitkamani4732 2 ай бұрын
Here we are averaging distances but we are calling it a velocity... How its possible? Shouldn't we average displacement?
@saurav-zw3lh
@saurav-zw3lh 4 күн бұрын
its displacement
@milroydissanayake886
@milroydissanayake886 Жыл бұрын
Super catch.Keep up the good work
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Thanks, will do!!
@vinodhc5239
@vinodhc5239 Жыл бұрын
Instead of video u publish physics textbook sir.
@PhysicssimplifiedbySunilBalani
@PhysicssimplifiedbySunilBalani 5 ай бұрын
Drift veocity is average of drift velocity of large number of electrons and for each electron a is qE/m this can be checked in "drift velocity and collision time" by Donal M Title American General of physics. Lastly in my humble opinion in science we are all learning it is about betterment not about being right and wrong.
@user-sk9gc7ie9n
@user-sk9gc7ie9n 6 ай бұрын
See prof. Verma has derieved ohm's law using his equation how do you justify that
@RchandraMS
@RchandraMS 4 ай бұрын
This page that you are showing doesn't exist in Feynman lectures series.
@supersomething3979
@supersomething3979 4 ай бұрын
www.feynmanlectures.caltech.edu/I_43.html#:~:text=The%20drift%20velocity%20of%20the,in%20a%20unit%20of%20time. search under drift speed
@suryabartasaha341
@suryabartasaha341 2 күн бұрын
It exists.
@causality5698
@causality5698 5 ай бұрын
I don't get it how (sig(tn^2)/sig(tn) = 2*tau) To simplify, let Tau = T If tn is the time taken at each instant n. If T is taken as time at each instant, "dtn" becomes the error tn = T + dtn => our expression becomes sig((T + dtn)^2)/sig(T + dtn) Simplifying a bit, sig(T^2 + dtn^2 + 2*T*dtn)/(nT + sig(dtn)) = (n*T^2 + sig(dtn^2) + 2*T*sig(dtn))/(nT + sig(dtn)) Evaluating at limit n -> infinity, = (n*(T^2 + sig(dtn^2)/n + 2*T*sig(dtn)/n))/(n*(T + sig(dtn)/n)) = (T^2 + sig(dtn^2)/n + 2*T*sig(dtn)/n)/(T + sig(dtn)/n) Finally since n->infinity, sig(dtn^2)/n = 0 2*T*sig(dtn)/n = 0 sig(dtn)/n = 0 => Expression becomes T^2/T = T Where does 2*T come from :P
@CHIRUMANI25
@CHIRUMANI25 10 ай бұрын
what do you prove foriegner is right
@alberttesla3417
@alberttesla3417 Жыл бұрын
Yes u r absolutely right
@sambitsa5025
@sambitsa5025 Жыл бұрын
Even walter lewin said about this, may be you should check his video
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
I remember him deriving this in like 2 seconds without diving deeper! :D
@sambitsa5025
@sambitsa5025 Жыл бұрын
@@Mahesh_Shenoy keep up the good work bro. You are helping me more than my school teachers do
@anirudhgoyal5603
@anirudhgoyal5603 Жыл бұрын
and just a suggestion you really should start teaching jee aspirants :)
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
I find that dull & boring :-/
@anirudhgoyal5603
@anirudhgoyal5603 Жыл бұрын
@@Mahesh_Shenoy well you can make it fun !!!
@TechsumitX
@TechsumitX Жыл бұрын
Nice
@sudiptabasu96
@sudiptabasu96 Жыл бұрын
Excellent work and please keep up the good work. The problem is that a large cross-section of world population continues to live with tribal mindset and herds mentality even today. And we human beings are not to be blamed for this - indeed we lived the life of herdsmen and tribes million years back. This gives rise to cult following. Once somebody becomes a CULT - he becomes a GOD - other members of the tribe won't allow you to question that CULT - that's why you get to Jaggi Vasudev, Ramdev etc. Two years back I got into an argument with some kids over a KZfaq video by H.C. Verma - question was regarding the magnetic effect of a moving charge. I found H. C. Verma's explanation rather naive and incomplete and I have seen many such flaws (of Prof Verma) before. I commented that Prof Verma loves Physics and probably wants to learn Physics, but he is NOT an expert. This irked some kids - some of them appeared and probably about to appear at IIT JEE. They immediately started to throw their weight around by flaunting their IIT JEE ranks and all - which of course I won't cross-verify. I off course won't throw my weight around saying I completed my B.Tech in so and so year - did my Masters in so and so year - happened to work in so and so Semiconductor MNC Majors in so and so places and in so and so positions and took part in so and so R&D projects and that my son is a student at so and so IIT at that point in time. Honestly, when I wrote IIT in 1998 paper pattern was 40 X 2 + 15 X 8 in three hours - my son thinks it was tougher then paper-wise may not be competition wise. And anyway, an IIT rank itself isn't a testimony of one's understanding of Physics. I just tried to be humble. But finally I had to say that Prof Verma is more of a HYPE and a CULT. And it is extremely difficult to convince others that CULT-FOLLOWING isn't a good idea.
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Thanks for this very thoughtful comment! But, I think prof. Verma is really good. His books are extremely helpful. It explains things very deeply and in a simple language! It's because he is so good, it's worth pointing out places where I disagree :)
@theUnmeshraj
@theUnmeshraj Жыл бұрын
I remember you commented on his video.
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Yes! Yes, I did!
@solitonacademy
@solitonacademy 4 ай бұрын
Underated person HC verma got a good award not working for online videos spend time on solving problems with pen and paper. Your demise to do stupidity. Badma bhushan for Sir HC Verma.
@user-ie5mm3ie4k
@user-ie5mm3ie4k Күн бұрын
thanks
@mamatashrarma5194
@mamatashrarma5194 Жыл бұрын
Sir khanacademy pr 11th class ki science ka content thoda zaldi daaliye
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Coming soon!!!
@Trenorts
@Trenorts 3 ай бұрын
My commerce brain is not gonna judge both.
@VilexerCreators
@VilexerCreators Жыл бұрын
He is not wrong even hcv made a video too you can check it out his channel
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
I saw the video! And I explained why I still disagree with it :)
@retrc0
@retrc0 9 ай бұрын
i think its 1/2 at^2 cause s=ut+1/2at^2 s=l u is u t is tau a is a and u will be 0 as after the collision the electron starts afresh hence l=1/2at^2 (t is tau) does this justify it? i am not sure thats just what i think but thing where i also cant wrap my head around is why are we talking about such short distances when the book mentioned l is a distance in a long time
@sibub21
@sibub21 Жыл бұрын
Good work 👍
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Thanks :)
@Nikhilkumar-on8vg
@Nikhilkumar-on8vg 6 ай бұрын
Average speed= (Average diatance / Average time ) is not the correct approach. Averge speed= ( Total distance/ Total time) is the correct approach.
@qasidnawaz3267
@qasidnawaz3267 Жыл бұрын
This video gonna be viral
@anujbillore3740
@anujbillore3740 Жыл бұрын
This thing is known by every JEE Aspirant . I think almost every JEE Faculty knows about this error and tells the students about this
@dexter_pir
@dexter_pir Жыл бұрын
@@anujbillore3740 yes
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Oh, I didn't see a single explanation explaining where exactly the derivation went wrong!
@anujbillore3740
@anujbillore3740 Жыл бұрын
@@Mahesh_Shenoy You are actually Correct . They tell us about the error that it is given wrong in HCV and tell us the correct Relation . They don't really explain where it went wrong Keeping the relevant scope of JEE Exam.
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
@@anujbillore3740 It's one of the many reasons I don't really like how the mainstream JEE coaching is done! All the joy from science & math is reduced to solving numerical quickly and accurately! Exactly opposite of what STEM is supposed to be!
@danishhundal7639
@danishhundal7639 Жыл бұрын
My frnd just sent this to me :)
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Hope it was worth it!
@Harrykesh630
@Harrykesh630 23 күн бұрын
Mahesh, what will be your counter argument for this : "kzfaq.info/get/bejne/oKt7iNKYm5OwmXU.htmlfeature=shared"
@VijayKrishnanFlipora
@VijayKrishnanFlipora Ай бұрын
This explanation is incomplete. You are right that due to the effect of variance, HC Verma's value is an underestimate. But there is no reason why the correction factor is multiplying by 2! The correction factor can be a any arbitrarily large positive number. Proof: Correction factor is [(t1^2 + t2^2 .... t^n))/n divided by [(t1 + t2 + .... tn)/n]^2 suppose t1 = t2 =t3... = tn = 1 (distribution with 0 variance); then correction factor is 1. But suppose t1 = 1 while t2 ... tn is 0. (distribution that maximizes variance). Then correction factor is (1/n) / (1/n^2) = n n can be made arbitrarily large is unbounded. All you've proved is that drift velocity lies somewhere between HC Verma's answer and Infinity. You've not proved that twice of HC Verma's answer is correct.
@satyabachan8164
@satyabachan8164 Жыл бұрын
Dear Mahesh Shenoy, Beta Physics is all about concept. Beta you have to clear your concept first then dare to prove wrong someone like honourable prof. H C Verma ji.
@suryabartasaha341
@suryabartasaha341 2 күн бұрын
If you insist on worshipping authority then you should know Richard Feynman was one of the founding fathers of Quantum Electrodynamics ,won the physics Nobel prize in 1965, and he clearly said (in Feynman lectures on physics Vol 1 under section 43-3, heading: Drift velocity)the 1/2 factor formula is WRONG and the other one is correct and explained why it is so. I am not in authority worshipping and I believe anyone can make mistakes but if you bring honour, reputation etc. then I have to mention this fact.
@dipeshmalik6865
@dipeshmalik6865 Жыл бұрын
Yes sir you are right hcv sir has done wrong
@shivammittal551
@shivammittal551 Жыл бұрын
Lol right now i was cramming this formula for my jee exam
@Mahesh_Shenoy
@Mahesh_Shenoy Жыл бұрын
Haha!
@wasifulalam1393
@wasifulalam1393 Күн бұрын
your math is wrong as well @6.30 min
@OnlyLogicWins
@OnlyLogicWins 2 ай бұрын
Hi FHP, Does electrons really push each other in a circuit Or is it really the field interaction? Can you make a video? I found the following discussion interesting: kzfaq.info/get/bejne/hZOHdr1ptdHWe2Q.htmlsi=Ggb4Y4Ud2VjThVFr If it doesn’t physically push does the equations apply?
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