We generally take potential difference across the connecting wires in a circuit as zero. Still there exists a current in these wires. How? H C Verma answers this question.
According to me as Va and Vc are at same potential but Va and Vb on both sides of resistance have potential difference then I= v/R flows through ckt And also if va = vc then means potential difference is zero so if there is no resistance between va and vc then 0/0 form so if resistance is not connected in whole ckt we could not determine current but as resistance is there so by ohms law we can determine current so to determine current we should have resistance or impedance( in ac)
Hello sorry I might be a nuisance but in our preboards examination(class 10) we got a question quite similar to this which I am having a trouble to understand and no teacher of my school is being able to give a reasonable answer without defying past concepts. If u ppl could help me out it would be of great help.🙏
@@aditya2892 so hey , ik your boards are coming and it's just right to clear every doubt you have , so here comes the explanation While dealing with circuits and electricity , in general cases , as we say ideally , we consider the resistance provided by external factors negligible , but since the question here is asked that if there is no potential difference between the two points A and C , then how does the current flows , we have to take the external factors and also the configuration of the wire we are using for the circuit alongwith it's material so yeah that's it , it is the simplest I can get to since you are still in 10th Lastly all the best for your boards !!
I had book of HC Verma in year 2001 , that time I was in 11th class. My teacher, VK Handoo told to go through HC Verma... Though I managed to buy but never managed to get that level of potential in myself to read and understand it.... It was very very good book that time. One of the finest book that time. I never imagined that I will see its author one day.... Especially in you tube.... I'm surprised that after around two decades after I purchased I will be able to see HC verma sir, giving lectures on his books.... Glad to see this... Our generation is very unlucky that we don't had RU-vid in those days....
His simplicity in delivering lectures in an example which we young generation should look upto....man with knowledge + man with value = a real man..thank you sir.
I think this question is the same as asking how an object in frictionless space can travel with a constant velocity despite not changing its potential energy. It does so, because objects in motion must remain in motion until acted upon by an outside force. In this case the electrons in the wire experience a change in potential energy across the resistor that provides them with the kinetic energy to complete the circuit. The motion of the electron through the "frictionless" wire is not due to a potential difference in the wire, but to conserving kinetic energy in the absence of an outside force.
For people who didnt understand , heres the logic , you have 2 tanks at the same level connected with a pipe so no water flows because they have the same level of water , as soon as you connect a 3 rd tank to the 1 st 2 tanks with less water, the rate of flow of water from the 2 tanks which have 0 difference in water height start flowing and their heights decrease at the same rate filling the third tank . So verma sir s logic holds good
You are the my inspiring Sir. You are the gem of India. One of the greatest teachers of Physics of the century. Very kind hearted. Yes, MIT has Walter Lewin sir. IIT has H C Verma sir. May God bless you all the time and be happy sir. Lots of love from Assam, India Thanks a lot for the video
If I remember correctly, the Ohm's law states that current (I) is proportional to the potential/voltage and not the other way around. So I °< V. °< is used by me for proportionality symbol. And R is an entity independent of these two (current and potential) and is a proportionality constant and this will not vary. When I say it will not vary, I am talking about static resistor used. We can definitely use variable resistor but at a given point of time, it will be constant. Plus the negligible resistance from the conductor material which again should be constant and depends on the material/metal used. And when it comes to potential being zero, it will never be zero. There will be some negligible amount of potential difference which is very very close to zero. And hence, there will be current. 2 A is very huge but it was just an example used for mathematical validation of V=IR. In reality, that zero is indeterminate as you guys rightly said because that value is very close to zero. Let's say 1 mV or even less and a negligible resistance of < 1 ohm from conductor assuming 0 for resistance like sir said. The value will have more zeros after the decimal point and in reality something dividing by something will give a value no matter how small both values are and hence that value is current which is not zero. Hope this is useful 🙏
In the qn potential difference btw A and C is zero But not the potential, so it's always fine The Qn is quite normal but the way the Qn asked was tricky
@@logeshgopi4212 yes. I think ohms law is valid for closed loop. It also works in "short circuit" condition, where the resistance of connecting wire (>0) plays the game. Am I correct? I think the same thing happens here.
Good observation Subhankar. In job (10years after I completed 8th std) while designing a circuit, I realised that my teacher forgot the assumptions and it never stuck me. For every concept, all assumptions must be included so that students understand concepts perfectly.
BIG FAN SIR AWESOME METHOD OF TEACHING, BOOKS THAT YOU'VE WRITTEN HAS HELPED A WHOLE GENERATION OF STUDENTS. MAY GOD BLESS YOU SIR, STAY HEALTHY, SAFE. SALUTE TO THIS GENIUS
Actually the current drawn from a voltage source depends on the external resistance ( here) or overall resistances present in a ckt. Current - effect , overall voltage diffence - cause...and it's value depends on resistance...so it never see the potential difference somewhere locally zero or not....this is the concept he is trying to convey us. Ohm's also satisfied in the region where potential difference is zero.. Thanks sir...great explanation...
If anyone is feeling weird about 0 being on both sides of the equation, it's not 0. There is a little amount of resistance offered by the wire and that section of wire has a potential difference twice the amount of that resistance. Keep this in mind and watch the video again and you will get it. Edit: twice because current is assumed to be 2 amperes
I have a question - what if in an ideal situation, the resistance of the wire is perfectly zero? Then ohm's law just breaks down because current 'i' would be undefined-?
This proves that in present time best education doesn't matter but advertisement matters. that's why other platforms have more than 5 million subscribers and HC Verma have only 500k .🙏
I remember this doubt getting raised in my mind in my school days but it was cleared when I got to know that every wire has some resistance and this is just a representation
Sir mera bhi bilkul same doubt aur Maine Kafi time iske liye search kiya but muge koi solution nahi mila but at last RU-vid recommended me your video and my doubt is cleared .you are a great teacher sir .thanku so much.
Super question My explanation is...... If u measure Voltage with reference of ground. Both points A and C have some potential becoze internal resistance zero. Va-Vc=0, but where as in practical we get some very minor voltage drop bcoz no material shows 100% conductivity. At the same time point B we found some dropping of voltage .
Thank you sir and the student who asked this question. It indeed was a great question. I never thought about this untilll now. Sir, huge thanks for the beautiful explanation.
Yes... absolutely correct...0/0 is indeterminate.... ohm's law is completely followed no matter the current..u have a pretty firm grip on fundamentals..👍
Hold on. How can you possibly get zero resistance? You cant just neglect the total resistance of a system. Additionally, if there is no pot difference or voltage in the system, how can current be generated? I dont think that its possible. Please correct me if i am wrong
Theoretically, but surely in a practical example it is impossible to ever have 0 ohms resistance, as even in a wire or in any component there will be at least a negligible amount of resistance thus requiring at least a negligible amount of potential difference for any current to flow. PS: I love your lecture style and you explain the concept really well!
I am not a student of physics still I use to come here to attend the lecture......Thats reminds my NEET preperation when I was in 12th.....H C Verma Sir is 💓
So proud of our very own 'The Explainer' - à la Feynman. Never knew the legendary Verma Saab had a channel. Thanks for making Indians enjoy and fall in love with Physics. God bless you Sir !
The answer to this was clear to me when i took R of CA as negligibly small instead of being zero.(since, conducting wires do have a small resistance). i in CA has to be equal to that in AB assuming it's a steady current. So the i in CA is some finite value. Then, using V=iR for CA, you see that since R is really small, V of CA becomes negligibly small. So there is a potential difference between CA it's just negligibly small(and because the resistance is also really small, a good current can still pass) (Pls correct any mistake)
HC VERMA CONCEPTS OF PHYSICS VOL 1 AND VOL 2 *BEST* BOOK EVER. YOU ARE MY SAVIOUR SIR🙏 NO OTHER BOOK WHICH I HAVE READ EXPLAINED THE CONCEPTS AS CLEARLY AS YOU DID SIR🙏🙏🙏🙏🙏🙏🙏🙏 THANK YOU.
HC Verma sir is saying only about Vc and Va or Vc and Vb.Not about Va and Vb .There is a potential drop across Va and Vb due to the battery. So current flows from higher potential to lower potential. Now I think his explanation is complete.
But the real question is not about A to B . It's about A to C . A has higher potential compared to B , so there will be a current flowing from A to B (which makes complete sense) BUT , why the same current is flowing from A to C ? A and C have same potential , so according to that , there should be no current flowing from A to C.
Dear sir if current is to calculate in this case and potential difference is zero and resistance is also zero. Current will be zero as per equation I = V/R
So far I used to think that resistance shown in the figure is not just acting within that length .I thought that resistance equally spreads over whole wire and only for good understanding we show that at perticular length .
I have no words to describe my emotions after seeing this video 1st time in my life youtube recommend me such a nice video which made my day worthy Thanks to RU-vid India 🙏
Sir, you explained that current that flows is logically correct but the question is WHY DOES IT FLOWS AFTER ALL?? reply to my comment. _Problem Resolved :-_ *Battery produces potential difference and this causes current in circuit (wire+resistor)* and... This current when flows through circuit *creates potential difference in various sections of the wire (in this case between A and C)* _THIS IS THE MOST ACCEPTABLE ANSWER TO WHICH I HAVE ARRIVED AFTER SEEING YOUR COMMENTS...THANKS GUYS FOR REPLYING TO MY COMMENT AND CREATING AN ENVIRONMENT OF HIGH ORDER DISCUSSION._
Current will flow because there is a path to flow..and something forceing to charge carried electron to flow on this path..simple...you can assume a dam(water reserver) ..flow of water as charge and storing that water mean storing charge n we call it voltage
Alot of didn't get the question . See in the free body diagram , a current(i) is flowing from A to B which makes sense because potential of A is higher than potential of B . But the question is WHY CURRENT IS FLOWING FROM A TO C ?? Potential of A and C are same but still there is a current flowing from A to C . Why ?
@@darkseid856 if u have vertical tube marked 3 points A, B ,C on that tube , u connected pump at the top (C) then water flows in the tube from A to B to C , then tell me why water flows from A to B while level of B is higher than A
Sir, i think the question he meant was that. How current can flow in that wire from A to C in spite of the potential difference between a and c is zero.
I think we should think it reversly....current i produces potencial difference V = ir when it goes through a resistance R ....here the resistance of the wire is negligible....so in that portion, potential difference created by current is also negligible.. The main point is- the current is produced by the potential difference of the battery.....not by the potential difference between two points on wire. Again i am saying-- Potential difference between two points of wire or say through a resistor is created by the current and the current is due to the potential difference of battery
He made an assumption that the potential difference from A to C us zero, but in practical it is not possible because of some negligible resistance. But still if you consider zero potential then resistance is zero and current will also become zero.
God of physics 🤚🙏🙏🙏 Hats off to u sir , please teach whole 11th and 12th physics for jee we will be delighted and our concepts would become strongest ... Please sir 🙏🙏🙏
as we know there is no force required to move a body in an uniform motion provided there is no friction.. similarly if there is no resistance(friction) the charge keeps on moving without potential difference(force) and hence there is current.. as in case of superconductivity
Every body : How nice he teaches physics 😳😳😳😳😳😳😳😳 Me : Sir the question says that it is a battery and you have drawn a cell (Only 10th students will understand)
I am blessed to see you first time Sir through this video. I hope you will keep us blessed with some important videos that you think is appropriate and must for your students.
I have an answer Think of this analogy of current as water and height of water is potential The pipe(potential) is horizontal upto point A and then it inclines downwards upto point B. U can imagine the water flows in the pipe. Now it's like asking why water flows till point A although it is at a same height
Yes current can flow only if there is a potential difference... But it is not necessary to have a potential difference between any two points, instead there should be an overall potential difference in the loop in which current flows.. Example: if you short circuit a cell, that is connecting positive terminal directly with negative terminal with an ideal conductor, then there will be a current flow even after having zero potential difference across the wire. It is due to the fact that the cell creates a potential difference in the circuit. We are lucky for getting blessings from you in the form of classes sir.. 🙏🏽
Having current without voltage is easy to understand and explain ... So imagine you have two empty 2 liter soda bottles, now imagine connecting them with an airtight tube that has valves on either end... now imagine pumping one side up full of air pressure and sucking pressure out of the other end... now imagine opening the valves. That's how you have amperage *with* voltage the air is the amperage and it rushes into the other bottle because of a difference in pressure potential... (voltage)... Now imagine a new experiment where both 2 liter bottles have the same amount of pressure this time, and opening the valve... some air molecules will still slowly meander from one bottle to another... those air molecules are current that's not being pushed by a difference in pressure therefore there is no voltage just amps. Hopefully that helps some understand. I can see people being frustrated trying to relate to how this works on a mechanical level. There are some neglected nuances like it's actually the missing electron in a conductor's molecule's valence shell that moves... one molecule steals from it's neighbor and that one from it's neighbor, on down the line so it's actually the gap or hole that is electricity not the electrons themselves. When you get shocked your being depleted of electrons... but this is just an analogy so of corse it will blow over stuff like that you'll have to visualize the actual mechanics on a molecular level on your own but this may help get you most of the way there. P.S. Per the 'Ohm's law cartoon' (what my analogy is loosely based off from), resistance would be a narrowing of the tube. The bottles are the positive and negative terminals of the battery. So if your going to run the example he gave in your head, that's how you'd extend the analogy.
@@voidmain7954 Thank you, I honestly wasn't sure if it was going to help anyone. Since you let me know that it did, I edited it, to expound on some things. Thanks again for the feedback, cheers.
Sir I had finished 12th grade from TamilNadu , I too have same doubt but not even satisfied with your ans. sir → I looks trivial please give molecular reason sir👍thank you sir😃 Sir and since if *i* = 0 too satisfies that condition As V= iR → 0 = 0x0
I m even frm tamil nadu.....the question is even though the volt is 0 the current flows in it...why...that's why he is giving explanation for that...even potential difference and resistance is 0 the current may vary.
Sir is saying that practically the resistance in the wire cannot be zero, so the current will definitely flow the potential difference will be created to the resistances in the wire.
bro my explanation is regarding magnetic field...that is magnetic field can also exist even if potential is zero....and that magnetic field can cause the charges to move?...i may be wrong
@@ashutoshwalia2316 nah,actually the magnetic field has a kind of limited affect on moving electron.just think of a planet orbiting around sun it's constantly getting acted upon by a force perpendicular to it's tangential motion which changes its direction,but ultimately planet's energy remains constant even tho it's under a force,the magnetic field has a same affect on moving electron(it kinda affects only its direction,no energy change), whereas electron under potential difference accelerates and thus keeps on gaining energy. Hope it was clear.do dm me back if u feel its wrong.....
I feel soo lucky that H.C Verma sir is teaching me through youtube :) I came here because I don't understand the Electricity chapter, so thought to teach from H.C.Verma sir
मैं explain करता हूँ... 1.) अगर conductor का resistance ZERO (R=0) माना जाये तो, सर का explaintion समझ में आता है 😊।। 2.) But, अगर Conductor का Resistance ZERO नहीं माने तो ( R#0) --- Potential difference, current का folw होंने का कारण होता है, इसका ये मतलब नहीं होता की जहाँ potential diffrrence न हो वहां current flow ही नहीं करेगा plz understand।। जैसे की water को flow होने के लिए हमेशा ढालान(slope) की ज़रूरत नहीं होती है, उसे pressure या Inertia के through same level होते हुए भी Flow कराया जा सकता है। ठीक वैसे ही यहाँ...... Point C to A, P.D zero होते हुए भी current flow होगा, क्योंकि ये सभी setup battery +ve & -ve Terminal से जुड़ा है, और battery अपना काम करेगा ☺️☺️।।
Potential difference, current का folw होंने का कारण होता है, - Galat hai. Current ka flow potential difference ke karan hota hai. I is proportional to V hota hai. Concepts of Physics me sir ne is baat ka zikr kia hai.
If he started this channel at the same time when he wrote those amazing books, It's infinite* times sure that he beats the record with other top popular edu channels, in india.
