0:00 Rakshak Sir Teaching Chemistry Before GTA Six. Rakshak Sir Teaching Biology Before GTA Six. Before Buy GTA Six Don't you even think about what is going to happen? Can't. Ok? Because the protector sir Teaching Class 12th on His Own Channel and First This chapter is electric for you guys. [Music] Charges and Fields, which you guys over the very very very heavy demand of It is being uploaded. because you people All the brothers were in the comment section. He had filled that Sir for class 12th also Bring something, bring something for class 12th also, Start one shot for class 12th also. So Brother for that right now [music] this detailed one The shot is started. I dedicated this chapter to prepared in such a way that as much as Whatever derivatives there are, they will all be included. All the theories will be included. Previous year questions will also be included. I make a lot of things here with my own hands I am going to do it. That means this is for some revision. It is not a one shot. So don't be confused.
0:47 This is a detailed one shot. Everything inside it Will be covered. And after reading this chapter You can directly go and solve the NCERT questions. If you attempt this also then you will understand the question I will start coming. in the description below If you click and see, you will see a Telegram You will find a link where you can access these notes. Will be uploaded. So tension at all I will not take it. As soon as the lecture is uploaded After some time on Telegram also The notes will be uploaded. Ok No? [Music] Let's not waste any time Let's start our first chapter Electric Charges and Fields. Start The story is about the charges. So brother You all know that there are two types of charges. There are. Positive and negative. negative Fundamental intrinsic charge of electrons It is considered property. Similarly intrinsic property of the proton That is, what does the proton charge show?
1:34 Is? That is a positive charge. So two types of You find charges inside the atom itself. Positive charge is found inside. In protons Isn't it? Which resides inside the nucleus. And who roams around? negatively Charged electrons move around. These basic The atomic model is what we all have in our minds. I have been sitting here since class ninth. Ok? Let us understand the meaning of electric charge. What is a bar? Look Electric Charge is actually an intrinsic property It is about matter. Okay, right? Someone asks you to What is the charge? then it is property of Matter. And what kind of property is it? intrinsic This is called property. What kind of property? Intrinsic property. This is intrinsic What is the word brother? Look, intrinsic It means pure. of intrinsic It means his own. So, it means matter His own property. Like a sweet brother What is the property of? that she is sweet
2:20 Will happen. Have you ever heard of sour sweets? No. What are the properties of water? that he It will be cool. Isn't it? cold water speaks As. What are the properties of fire? So the fire It is an intrinsic property that it is hot. She will do it. Similarly, a piece of matter The intrinsic property is charge. Now Charge also has SI units, brother. And This is coulomb which is also known as ampere second. They say. Moving away from the current formula Let's come. Whatever you did in class 10th I had read this one. I = q / t so from here q IT becomes what it is. Isn't it? So this Ampere came from current and time came from Seconds. So you need to look at ampere seconds. If you find it, don't panic. Okay, right? So Say coulomb and say ampere second, it's the same thing. Is. There are also some CGS units. take a quick look Let's go. It is not used much. This is called an electrostatic unit.
3:05 Unit of charge i.e. ESU of charge or Then it is also called start coulomb. If If you want to remember this, you can also remember that One coulomb is 3 * 10 to the power 9 There is an ESU for any charge. Ok No? So it is called ESU of charge or This is called start cool. This is its CGS unit. So these are the big things Done about charging. Okay, charge it Denote by q. Ok? remember this You should also remember that sometimes capital q is used here. You will see it happening and mostly you will see small q use It will seem to happen. Both of these letters There is a denotation of charge. Let's move ahead We people. It comes to a very variant property which is called Quantization. Look, there are many charges. All the properties are there. Like there is additivity. Additivity means that the charge is the scalar property. on any body
3:51 How much will it cost? Add all those charges You will get it by doing it. That is, directly What are charges? There are ads. scalar There is property. This is called additivity. Then comes another big important property. Which is called conservation of charge. These Keep writing together. Isn't it? copy pen Take it and sit. Just popcorn and watch a movie You don't want to see it brother. Copy and pen with Keep a diary and pen with you and take notes. Please go. What was the first property mentioned? I have? Additivity. The second property I am telling you. Conservation of charge. Conservation means that charge is not Never before created nor ever before destroyed charge It is possible This is absolutely matter i.e. mass It was never made in the same manner and never will be Will be destroyed. The same charge as before It is still the same today. It will remain the same in future also. just one Transfers keep happening from one place to another. This was the second property. Now the third and most Important property which is also questionable What comes next is quantization. I to you
4:38 What did you just say? I said charge What can happen from one body to another? Is? Transfer may happen. That is, charged It can be done, charge can be given. i.e You can give me the charge. You charge me You can take it. Isn't that right? So when charging If someone gives or takes a body, then to whom does that person belong? Does she give and take according to the calculation? He gives the account Quantization. Quantization means Have to make packets. So nature charged The packets are defined. packets Have defined it means that if you have any If you want to transfer charge from body to body then You will be able to give it in multiples of e. of Multiple means multiple of electron. Multiple meaning of electron The charge of an electron is called e They call. Look at this, look at this, it's written here It has happened e. This is visible. e is written This is e. This e means one
5:24 electron charge and the charge of an electron Charges 1.6 times 10 to the power -19 coulomb means that much charge you can give at one time You can transfer If you want to do more, double it. If you want to do more than this then it will cost three times You will have to multiply it if you want to do more than this Four times that, that is, one electron Half an electron can be transferred If you don't break it a bit, will you transfer it to me? Did you understand the point, pieces of electrons? Neither electrons can be transferred The transfer will be complete. That is, when the electron If there is complete transfer of electrons The entire charge will also be transferred. Understood? So neither in charge fraction can be taken. That is, the electron We cannot break it into fractions. Na can be taken in decimal. So this The total of the natural number will be taken
6:09 In form. So what is the formula here? Is? q = ne. What does n mean? Number of Electrons. So how many electrons are there? Multiply by how much? on an electron There is charge. You will multiply both and get the total. Charge on the body will come. and the value of n Anything can happen. It can also be zero. That means zero means there is no charge. Yes. It can also be plus or -1. Plus for whom Will it happen? will be for protons. Minus whom Must have taken it? It will be for electrons. Brother Protons can also be transferred, right? And The charge on a proton is the same as The electron has a charge. So this It is called electronic charge. What Do you call it? It is called Electronic charge. what do you call Son? This is called electronic charge. You must have understood. No difficult thing Is. Isn't it? Look what you wrote here, friend. Has it happened? The charge units are those of e are given in terms. Like 1E, 2ee, 3, 4E, 5, 6 It can never happen that
6:58 5.5 Charge transfer is taking place. that 5 1/2 Electrons are being transferred. Is this so Can it happen? Cannot be done. So my Hopefully you must have understood the matter. Once Read it. What is the definition? The Quantization of electric charge means That the total charge i.e. q of a body is Always an integral multiple of basic Quantum of charge and basic quantum of What is the charge, that is the basic packet, it is e Meaning the charge of the electron hopefully gives you You must have understood the point, let's move ahead now. It comes to what are the methods Look brother, there are three methods of charging. Total as given in your NCERT The first provided charging by friction, The second given is conduction, the third given Induction has happened. I listen to it quickly. A little detail of two of the three
7:44 C is more. Cut down the details of one considerably. NCERT. Well then. as much as any I will explain everything to you in detail. First of all let us come to friction. See how friction charges the body. Is? Whenever you rub two bodies. For example, suppose this is a road and this is a cloth. These If they are rubbing against each other. These among themselves What are you doing? If God is doing it then Some electrons gain energy from heat They get transferred into another body. So the body from which the electrons come out She will become body positive. and in which The electron will come and sit because The charge of the electron is negative. They How will the body become? It will become negative. Got it, right? So this is called charging. By friction. electrons transferred By rubbing two objects. two objects Rubbing causes electron transfer Is. Two examples of this are very important. Which you have to read. One is glass
8:30 Example of road. The second is ebonite. Example of road. Okay, right? So Glass Road rubbing against silk. And the ebonite rode with fur or wool Show it rubbing. Fur in many places It is written. Wool in some book It is written. It's the same thing. any problem No. Ok? So Ebonite Road if Wool If you rub it with where to where will the electron go? Similar glass road silk If we do this with then where will the electrons come from? Will you go? I have also given you a solution for this. had taught. One also taught RDX. Gin Do you children remember that RDX? Pause now and write in the comment section. I I'll see which child is already with me. I have read this topic. Okay, right? One Please do tell me once. Ok? definitely definitely definitely. Ok? Quickly, quickly. So I I I will move aside. Yes sir. So its RDX was that which was extracted from ebonite.
9:18 It is starting. It means Ebonite Road But the electron will come. i.e. Ebonite Road It will be negatively charged. and from wool Brother, he will come after being transferred. Isn't it? So this is it The wire will become negatively charged and will Positively charged. Okay, right? In this The opposite happens. In this from here to here The electron goes. From the road to the clothes The electron goes away, which means it becomes silk negatively charged and the glass rod becomes is positively charged. Remember this from E. E For ebonite. Okay, right? I also did the same I had remembered it. I will remind you as well I have been. Ok? Let's come to the second one. Second This is conduction, son. Conduction means That a body has a charge. Suppose there is a positive charge and the other body There is no charge nearby. He is chargeless. Assume that there are no charges against him right now. Has not arrived. So what did you do? You
10:04 Made them both touch each other. It is called Conducting. When you actually get touched You give it. Bringing you into actual contact To two bodies. That is called conduction. Here But look what is written? Direct Contact Allows Charge Transfer. as soon as You will connect two bodies directly. So the charge goes out from one and into the other The transfer will start. That is, one The body which was positively charged and the other body which Now that which was neutral has a positive charge. Understand that there was some positive charge in it We will come out and reach that neutral body. So the neutral body is already somewhat charged. will go and the already charged body will become something There will be less charge. Because its charge is So the transfer has happened, right brother? Oh, he is the one who He took money from his pocket and gave it to someone else. Neither did his rupee decrease a bit nor did the other The rupee increased. it had been. it is
10:49 Conduction. The rupee depreciates slightly where The charge comes from here. So okay? third It is induction. Listen to the induction quickly Let's go and see what it is? what is induction It happens? See On one side we bring a body which is charged it occurs. On the other hand, there is a body that That it gets uncharged. And without touching here But what happened? There was a touch here. Here But both were touched. wire to both Also connect to. This is also a way It happens. What should I do? connect to the wire Give. Like I took a wire from here. From this here Connected it with. So connect it with wire also. These There is also a method of conduction. But Look here, touch from afar means from afar Looking from. Don't let me touch you. Induction Remember inside there will be no touch. Then What will happen? What will happen is that the one who is positive about it Its electrons have a charge, right?
11:34 It will attract. The electrons which They will come out and this part They will come and gather in me. you talk to Understood? Two electrons from this entire body I will run and run and come running will gather here and here There will be a deficiency of electrons. Shortage There will be electrons Positively charged things make you feel more It will start appearing. positive charge here It will appear more. means one who It was a neutral body, one of his dice. Side charge was made. other side second charge I have arrived. Now what did you do with the back side? What has he done to me? Look, it has been interpreted Is. Earthing means a wire lead And put it in the ground. taking the wire to the earth What happened after putting it in? taking the wire to the earth By putting it in, whatever charge was there on this side It was all there, understand it in one way.
12:19 It got neutralized. Because there is earthing She is gone brother. If there is earthing then it is zero Potential is achieved. Zero Potential If found, then the transfer of charge to the earth Will be done. You can understand like this. Now this is complete How will the body become? be negatively charged Will go. What is written here? See. Charge separation arcs without direct Contact. without any direct contact Empty from far and wide What should be done with electrons? on one side Call him. This is called induction. Hopefully you must have understood. Moving forward Yes, it is quick. Now comes Brother Coulomb's Law. But. Look here about Coulomb's Law. But what is written? Coulomb's law says It is about the force between two charges. Look what is made here? one charge Here's one charge. in between the two Some r is distance. Isn't it? some distance Is. This charge, force on this charge Will apply. This charge on this charge
13:06 What will you plant? Will apply force. both one What will you impose on the other? Repulsive Force Will apply. So Mr. Cullum said that this The force that exists, the force that exists, This is directly proportional to whom? of multiplication of both charges. Here Take pay charge q1. Here the second charge is q2 Take. So the multiplication of both charges You will have to take it here. i.e. taking q1 * q2 Will have to. Correct? Good. Other than this He had said that brother this is inversely There will also be a proportion between the two. the square of the distance i.e. the inverse Square law will follow. Inverse Square What does the law say? He says brother charges the farther you take it between charges The more you increase the separation in the force It will reduce that much. So how about separation? Is? It is an inversely proportional relationship. If this is added then force is formed
13:51 Proportional Q1Q2 / R². and when The proportionality sign is removed, equal to is applied, so here is a K Apply constant. KQ1Q2 / R² and this K, brother, is called Coulomb's Constant. This is called K. Coulomb's Constant. Who is this K brother? This is it Coulomb's Constant. I will tell you its value What happens to you? This is Coolums Constant. Its value is 9* 10 to the power of 9. Let's talk a little about the unit. Late. You can remove it yourself To the unit. So don't worry. Okay, right? So what is the value of K? 9 * 10 to the power 9. Now what is this K? Look K actually It happens. This Coulombs constant is It actually happens to be 1/
14:37 4 is the number Pi itself. Look at 4π and then you get Apps 0. Who is this Apps 0 brother? Who is this? This value of 0 is called the permittivity of the Free space. What does permittivity of free space mean? Understand like this, brother, how much space? Allowance Tax These charges are being forced on each other You can understand this way how much he is giving to invest. Okay, so what does permittivity mean? That this also has some value brother, isn't it? So only then this value is created, only then 9 * 10 to the power of 9 is also not equal to 9. There is some value, let me write its full name first. I call it permittivity. of free space ok and it has value
15:24 8.85 What is times 10 to the power -1 unit? Let's talk about this in a while. Its unit and its unit too, how Does it come out? It is very easy to remove the unit. It is very easy. But I will tell you how to remove it. For now, I understand this much. Isn't it? f = k q1 q2 / r² means number of charges The more there are, the greater the force. Charges The fewer, the less force. Ok? And The greater the distance, the lesser the force The shorter the distance, the greater the force. So This story was told by Kulam Sahib. So this cool It was sir's law. This is called Coulomb's Law Brother. Ok? Excellent. Okay, now one more thing We do. Suppose these charges are It is picked up and placed in some medium. As Let's assume that brother, these were two charges. These Q1 charging. This one charges Q2. And
16:11 What did we do to them? in a medium Placed it. Ok? Here is Medium. ok sir? This is some medium. Now every The medium has a dielectric of its own It is constant. What is this thing? Go ahead and learn it yourself We. Okay, right? For now, you understand that This is just a value. It is called with a capital K Let's denote. This is small K, son. Cursive K is this one. This one is a cursive K. Is. This is called Coulomb's constant. I I am showing both on the same page so that You should never be confused about this. These The small K is the Coulombs constant. Is. What is the name of the capital K? Name with capital K is the dielectric constant. First its name I will write it completely. Dielectric Constant. Ok? So every medium has its own There is a dielectric constant. And when this
16:57 Now force will be applied between them like here The force that seemed to be this one is this one, isn't it? Do you know how much it will be now? He is now Will be divided by dialectic constant. It is very simple. Very simple. This means it still They are applying force on each other. q1 also applied force on q2. q2 also said yes to q1 Applied force. The force that is now being felt Look, if you are feeling like that then it is the old Force. k divided by die electric constant That means it will be capital K. This will take force. This will take force. Did you understand? This story Is. Ok? ok sir. So this force which Son, it seems to be from dialectic constant It seems to be divided. Excellent. moving forward Am. And let's talk about the unit now. Correct Is? Just look at a question. what is written
17:43 Is? saying two identical insulated There are copper spheres. A and B have there Centers separated by a distance of 50 cm. what is the mutual force of Electrodic repulsion between the charges on Each is so much. Okay, right? So here you The value of the charges has been stated. of both The distance in between has been mentioned. So how much Will force be used? So son, force yourself to relax like this You can take it out from there. Look, this one is a sphere. A This one is Sphere B. both on each other What are you applying? They are applying force. The distance between the two is 50 cm. Here you have a given. Okay, right? 50 cm It is given. Correct? and charges also given You have 6.5 * 10 to the power of -7 so the force There will be a formula between them. k q1 q2 / r². Just put it once. of k
18:30 What is the value? 9 * 10 to the power is 9. What is the value of the charges? 6.5 * 10 to the power of -7 and again 6.5 * 10 What is this r to the power-7 divided by? This is it 50 centimetres. So you will make it 50/100 and Please square this too, son. 100 Why did you divide it from? Because centimeters I was. The meter needs to be changed. That's why it is divided by 100. and Square Why did you do it? Because in the formula The square comes, son. Okay, right? Now you When you calculate this, I will give it to you. I am leaving it for you. It is a simple calculation. There is no difficult calculation. Easy It is a calculation. I leave this for you Am. I continue further. Let me come to the concept. Let me come to the logic. This is a good question. So look at this one Times. After this he is saying this. is saying one
19:16 There is also a third sphere. There is also a third sphere. Is. He is saying that it is also of the same size. We Said okay brother. He is saying but he It is uncharged. It is neutral. meaning saying Has brought him in contact with the first. Got him touched with first. means to him I brought it and got it touched with the first one. Correct? Say been then brought in contact with the Seconds. Then he took it and touched it for a second. Got it done. Well said finally Removed from both. Then removed it. Say what is the new force of repulsion Between A and B? Now he is saying that between them Find the repulsion force. me a Tell me the matter. When a neutral conductor is taken Came and got A to touch it. So is that his Will it take half the charge or not? Remember conduction. I just told you. Conduction What does it mean? that brother, whatever the charge Is
20:02 And if the second one is also an identical sphere If he goes, he will definitely take charge of it. Will go. Isn't it brother? He is charged with it Will go. Its charge will be reduced somewhat. Its The charge will increase. So you came and touched it. Got it done. Brother took charge of it. Isn't it? So If you took it, how much did you take? Took half. take half Went. And then by taking the same charge you I touched on this. So now the average of both The charge that will be there, the charge that has come from here, The sphere has arrived. Isn't it? He and what he has The average of both charges will be the remaining amount. Near B. Did you understand the matter? So, first of all, If it had a charge Q and it also had Let Q be the charge and the force be KQQ/ If R² was then what will it be now? Now it will be brother A's If we talk about pass A, then A has charge It would be Q/2, half of it is gone. So its
20:49 The charge will be Q/2 right? And what we are doing in this We brought the sphere C and touched it with B. Got it done. What will be B's charge now? Brother? What will be B's charge now? Look, first B had a charge of Q. Now suppose it comes from Someone touches C which has a charge Q/2. C was that third sphere, that Q / 2 Is. So tell me what is the average of both? will form? So look brother Q + Q / 2 / 2 so this much The charge will be saved. You understood, right? so how much Look, the charge has arrived: 2q + q ≠ 3q 3q / 2 / 2 means 3q / 4 this charge will be saved Brother. What is the truth? 3q / 4 charge Will be saved. Just the distance between these two It's still only 50. You can still use
21:35 Yes to this. Isn't it? This is a distance of 50 50 between the two. 50 cm Isn't it? Write down the new force that will come as f'. Now we cannot write f. f was written here So we cannot write f here. Here f' You will have to write. So what if you write f? will you write? k Square of q/2 and 3q/4/50/100. You just have to calculate it. Now what Tell me what the problem is? Values you already know Is. 6.5 is 6.5. Keep that here. The charge of q will remain the same. and these 3 /4. This is two so it's 3/8, right? These 3/8 Times will become the old f's. so one Work for whatever value it brings
22:22 Whatever value it gets, multiply it by 3/8 Just finished giving. It was very easy brother. To understand Came? But do you know how important the question is? To you? This is a question, brother. Very Variant question. Ok? means the brain He releases the horses. This is such a question. And I have not brought any light questions. I will not even bring light questions. Ok? Let's move ahead. Let's move ahead. Vector Let's also look inside the form Coulomb's Law How is it working? Ok? So Son, very nice to see in vector form It is important that you make a graph. y x ok sir? Created a graph. two charges Show. a q1 q2
23:09 q1 is exerting a repulsive force on q2. q1 q2 is applying repulsive function. any problem Not there. Ok? The position vector of both can be taken. Absolutely. So from here I write the position vector q1 of r1 Vector. Correct? and write the position of q2 vector so I'll write r2 vector. Correct? Correct? Good. This is between these two The distance is r, isn't it? So this To write it in vector form also I need to The r vector will have to be written like this. Direction something You will not have to give anything. So I directed Given towards q1 from q2. Okay, right? Given towards q1 from q2. Ok? Good. Now if I apply a triangle law Let me see here the triangle law of vectors
23:56 It happens. In that you know that brother when If we apply the triangle law, then two vectors Are showing. One showed an r2, one r Shown. And in this sense, if r1 is shown Then its net vector will become zero. So We don't show this, we will show R2 then. We will show R and then it will be equal to R1. Isn't it? So, we can write it as Brother, which is our R2 vector plus our The R vector is equal to what? R1 Vector K. So from here when I remove R So what should I write? R1 vector - R2 vector I will write. Magnitude wise will also have to be written. So R1 vector - R2 vector in mode I will write. Did you understand the matter? So this is the r No, this r here is actually r1 -
24:41 r2 is the mode of the vector. Now write force once Let's see. Come come. What is Force Brother? What is force? Force happens Sir k q1q2 / r² only magnitude wise It is written. Look, I did. So this is what the son wrote Yes, I have written this magnitude wise. Now Let's write it vector wise. Watch Vector Wise if we write it in vector form If we write it, we will have to put a vector over f. Correct? This became its magnitude. Yes. So KQ1 Q2 / R² is its magnitude. Correct It's a matter sir. well you know that You also have to write an R cap. These Brother comes for direction. Isn't it? Because you know this direction. Is. Force is being applied in this direction. So To whom did we denote this direction? R From the cap. Correct? Good. Now what is this R cap?
25:28 It happens? look any vector any A vector is made up of two things. One Its magnitude and its direction. If you want to write a cap, son, how will you do it? will you write? You will bring it to its divide. So Who got into the divide of a vector? of a The magnitude has arrived. Has it come or not? You will just put it here. k q1q2 / What will put r² and r cap? Vector Divide by Magnitude. Vector by Magnitude. So what is the r vector? Is it friend? Look at the r vector, here it is r1 - r2 and What is this r? r is the mode of r1 - r2. So If I have to write it completely then I will do it like this I will write. Look, I will write it like this k q1q2
26:14 r is a vector. Divide by these r² It is there and this is also there, see it will be made together r Isn't it? Together they will become r Just finally write it as kq1 q2 r vector replace r1 r1 vector - r2 vector r1 vector - r2 vector okay right and Divide by or put divide right here are the modes of the r1 vector - r2 vector cube Or write it like this, you understood, this r with r The one which is R mode is R1 - R2 mode Is. He wrote here and put his cube and Here is your R1 vector - R2 vector. This is the right way
27:00 Coolums To write the vector form of the law. These Coolums To write the vector form of the law. the most correct There is a way. Okay sir. Hopefully you must have understood it too What have I done? Let's come now Brother, on their units which we are behind Had left it. Let's look at some units. Let's discuss brother. See how the units It will be removed. units of k right And how will these come? Look and learn. you know The force is kq1 q2 / r², this is Is. Ok? So, whose units do you know? Is it in this? Just tell me this. Which ones are you Do you already know the unit? Just tell me this Two. Tell me. Whose units do you know?
27:46 Do you know about the force? Yes sir. Know Yes, it is Newton. Do you know about K? No Sir, I don't know about this. Leave it. charge Do you know that? Yes sir, it is Coulomb. So one coolam two coolam sir twice coolam. So Coolam Coolam will be written like this and what is this R? This is the distance. Distance is a meter In. This will be the square of the meter. So meter squared went up and coulomb The square came down. it became coulomb to newton meter squared square or n m2 c - 2 okay nm2 c - 2 is its unit Newton meter square coulomb-2 and one thing Tell me after thinking whether these k and apps 0
28:34 are not inversely related to each other Don't we have each other, then whatever is also its unit, its inverse unit, its Whatever unit of k is formed, it will be 0 That will be the inverse, so if that Newton That is n to the power +1. This is n to the power -1. The meter power will come to +2 here. Power-2 will come there is power-2 of Coolum. Here the power of coulomb will be +2. It's done unit. Did you understand? There will be reverse units, right? Buddy. Isn't it? So the unit of K is like this Beta Apps Not Unit is exactly the opposite of this It will be because it is 1 / K only. the opposite So it is. If you just look at the proportionality Is it empty? So it is K only. This makes it What became of the unit? n - 1, M - 2 and C + 2
29:21 End. I have arrived. End. Let's move ahead. Come on, this is also an important theory. Point is brother. Limitations of Coulomb's Law Sometimes it is asked within two numbers. Come listen. It says electric charges You should be on rest brother. If we go If there are charges then Coulomb's law is defined as It is not for him. Second Electric Charges must be point charges that is Extension of charges must be much smaller Then the separation between the charges. What is it Is it written? He is saying that the brother who There are charges, they are to be considered point charges. You. Now you will say that Sir, you have said that a b c were considered large spheres. Son I certainly believed in large spheres But is there any definition of how big it is? No, right? Did you give any definition? No. So The big deal is believing in big things. Meaning or meaning of assuming more distance or Assuming a point charge means that
30:07 They should be very small in comparison. Meaning The distance between them is so great that The charges may appear very small. As such Wants Coulomb's Law. Got it, right? this is what was written Look, it has happened here. Extension of Charges must be much smaller than the Separation between the charges. which charges There should be a distance between them, or it should be too much. Needed Size of as compared to charge. So This does not mean that point charge only You have to find that electron. You will not go looking for protons but you will find bodies. But she kept it at a good distance. Should be. Ok? Third, The Separation Between the charges must be greater than the Nuclear size. This thing is very important Brother. It may happen that you are Start studying inside, it's not about Coulomb's Law. Will get it. Study Coulombs Inside the Nucleus It is not a matter of law. There are coulombic Force doesn't work. nuclear over there F works. So understand what the main point is?
30:54 that if 10 to the power of 10 is smaller than -15 If there is distance then Coulomb's law works there. does not. So work over large distances Does. because of the distance less than So the Strong Nuclear Force Dominates over is written, isn't it nuclear? What will F do? Will dominate. Nuclear power dominates there. Whom? to the electrostatic force. So Understand the matter. The electric force is For large distances. of great separation Not for short distances They. This has been told here. Ok? Ahead Let's go. Coming next. Let's talk About the superposition principle. See, The superposition principle is not new. For the first time you have discussed the superposition principle Newton's Laws of Motion was studied in class In 11th. Never mind, I didn't read it either. So. The superposition principle means
31:42 Like there is a charge. Multiple on that charge The charges will deploy their respective forces. will put No? Like this is a charge. See. So this It will also exert its force on the charge. some of these He will also plant this, he will plant this and this also He will do the opposite, he will impose this on them also. Isn't it? So this dish, this relationship, It is mutual. Mutual means both of these is mutual. No third party interference ever It doesn't even happen. This is called the law of Superposition Principle. What is written? The Superposition principle means when a number of charges are interacting. The Total Force on the given charge is the vector sum of the Forcers exerted it due to all others Charges. Got it, right? Meaning, the vector sum of all Will be taken. Like, consider this on one charge. There is a charge q is not a charge. Its name is q not. Why is anyone even charging q1 on this?
32:29 Yes sir? He is applying force. F1 what is anyone even charging q2? Its He is applying force from above. F2 any q3 charge also What are you doing? applying force to it Is. F3 is the net force you want to see. We have to take the vector sum of all three and see. Ok No? The vector sum of all three will be f net Whatever will be, will be Will give you Final Force. f1 vector, f2 The vector that is equal to the vector f3 is That's what's going to give you the net force. fat the point is. Okay, right? This is what is called Superposition Principle. And look what he wrote Has it happened? The Force Between Two Charges Is Not Affected by the presence of other charges. The relationship that exists between two people It is between them. The third one will come, Will not be able to interfere. this way of
33:15 Bonding happens. This type of conversation There is a super position in the principal. Come Let us also look at one question. saying to Identical charges q each are kept at a Distance r from each other. ok sir. Say a third charge is laid on the Line joining the above two charges such that all The Three Charges Are in Equilibrium. It should be in equilibrium. what is the Magnitude sign and position? majority This is the question. This is not an easy question. good I have just brought the question. where the child gets stuck is where the child gets stuck, where the child gets stuck Problem arises. Let's see how the question Have to do it. I would have been a little to the side before Am. You see, are you able to do this? Come on brother, what is this question? Look at this question This is saying that there are two identical charges. q is both. This too q this too q. Correct? Here it is
34:00 Both. Correct? telling both of them to someone It is kept at a distance. Assume r It is kept at a distance. Here it is r Distance. is saying that the third charge q is also Placed. Where to place it? Value Let's take this and place this q here. Placed it somewhere here. Okay, right? Say I am joining the above two online. same Join on line only, join whichever line you choose. The charge is kept on top of it. Correct Isn't it? Telling the truth that all three Charges are in equilibrium. What does it mean to be in equilibrium? that being in equilibrium means everything Come to rest. No one should move. NetF on all What should happen? It should be zero. means q But even when both of them add 'f', the result is zero. Even on the small one in the middle, when these two If force is applied, it will come to zero and the corner Even when these two apply force on top, it becomes zero. Come. Son, this can only happen if this
34:46 The charge is negative. Think for yourself. accept this It would have been positive. Suppose this would have been positive. So would he have applied repulsive force on this? Would apply. Does this also impose a repulsive force on this? Brother? Yes, I would have applied it. He would have applied it on this also. Yes Would apply. If this is on this then how is F net zero Would? How does equilibrium come about? Thinking. so This will not happen. So this will not happen. it How should the charge be? staying negative Needed Now you please check it. On this charge Both of these will exert attractive force. harvesting It should be cut. It is attractive on this Will apply. This will put a repulsive cut on it Will go. It will put repulsive on it but it An attractive cut will be applied on it. This is how you To create a system. He is saying this. As such Make a system so that brother this -q charge has some value.
35:32 There should be value and some distance also. so come Let's see what distance we maintain then? Of Equilibrium is just sitting there. Isn't it? So let's do one thing. Let's do one thing. We Let us assume some distance from here. From where? It is between the capital q and the small q. Let us assume some distance x. How much did you accept? x I agreed. So what will be this distance? These The one will be r - x. Why do you believe that That is placed in the middle. a little earlier We can believe this. Hey, respect yourself a little bit already Can. Let you take a distance x, and another Consider r - x. Ok? Now on this Show equilibrium by doing balance at -q Okay, right? Where are you watching Equilibrium? Are? Looking at -q. How will you see? We will balance the forces of both. Come Forces writes. Look at the big q on the small q
36:18 Will apply force. That force will be k q q / x² Correct? What is the distance between these two? between? x is. Similarly, both these forces What will happen if you apply it? k q q divide by r - x Whole Square Quite a lot of you Children will ask Sir why you did not use this -q. Your son is just looking at the magnitude. Where are we concerned with direction? There is no meaning in direction for us So we are only interested in magnitude at this time so I just said here You kept only q and q, you could have kept minus also. Son, it doesn't matter either, take both. The minuses will also be deducted face to face so you Understand the matter. Okay, right? So there is no need There is nothing special to keep. Ok? now k q q kq
37:06 q cut off. What's left? The remaining 1 / x² = 1 / r - x² Take the root of both sides. let's take Sir. Taking the root will give us 1 / x. This will come to 1 / r - x. do it reciprocally Just once. Do it. It will come x. This comes will go to r - x. moved x over here, so that's 2x Went. 2x = r and x is r/2 This is your answer r/2 so where to keep it I understand sir, I should have kept it on r/2 only. Sir, why didn't you keep it in advance? Brother, you will have to prove that r Equilibrium is being achieved by keeping it at /2 only So where did I place the first equilibrium?
37:52 -q now the third thing here To find out the value of the charge, whether this value See how much you charge, this is what I asked. What is the magnitude, that was found out No, we told you that the sign should be negative. He should have explained it logically and position If you want to tell me the position then tell me the sin I gave the position, I told you the magnitude remained, come Now you can also calculate the magnitude. Balance the equilibrium in any one big q, do it on this or that, do it on whatever Do as you wish, okay, let's get to this big Q. Balance the charges means balance the forces Okay, when these two apply force, son. Big Big Q Big Q on each other so force will be written as K QQ upon me ye distance kitna hai sir r² This is great, now this small Q and big Q
38:38 Sir, if you apply then KQ small Q / this distance How much is it or take that one, let's just say one thing. Take it as you wish, it is what you like. You have got the distance, right? You have got this x. What is that? If it is r/2 then write r/2 also. You can directly do r/2 hole here. Square no problem, great. Now look, Who all will be cut, son? k went to K, q to q went, r² to r² also went. Isn't it? This also went Went. But this square of two is four. It will be made and will sit on top of four people. That means this q will become 4 q and small q will come. will go to q / 4 always with a minus sign. Why did the minus sign appear? You will understand. Is
39:24 No? I have already explained this to you logically. Has given. So whatever the charge is for this big Q If you divide the smaller one by 4, it will work. Will go. Divide by 4 should do the job Will go. So Q/4 is the charge of small Q. The magnitude has also arrived, son, the sign has also arrived. Son, the position also came. Okay, right? just Get a feel for the question. Is it right or not? Let's move ahead. Come on sir. Next thing comes Electric field. Look at the electric field We define it in such a way that brother, this in a space She does it. It happens in a space In space. Meaning we are talking about 3D space Is. Speaking of 3D space. this The method is shown with lines. Now we will study electric field line.
40:11 There is nothing to worry about. I am here I have come to tell you, brother, that How much is the field? his What is value? So listen. See How is it defined that let's say There is a charge. Ok? Q is the charge. He spreads his field in all directions Have been removed. Your field in all directions Have been removed. having drawn out your field Are. Now suppose there is a small figure in front of it. A small charge is required. A small charge q arrives Not. What is the name of this charge? q not. it There is a positive test charge. what do you call Does he have it? Positive test charge. who is this Is? This is called source charge. what to it Do you speak? The thick charge is called source Charge. What do you call this little one? Test Charge. When it is small in front of the thick charge There is a charge, right brother, so this is a small charge. He gets nervous because there is some big charge.
40:56 Can't uproot it. You understand the matter in small words Due to the charge, the force also applies to large charges. Even if she goes, he will not move. keeping it fixed The larger charge is the source charge. But what about this little one? small ones But the force will be repulsive. You understand this. Isn't it? So, the force acting on it is from the back. On the side. Will it feel like this or not? Absolutely It will take. You write this force once. How Do you write this force? tell me what would have happened Is? k q q not divided by this distance If it happens then you can take this distance as R. Ok? So how much did this cost? r² arrived. This Is the Force. I haven't written the field yet. Now! There is no talk of electric field. Now! Only force is being talked about. Ok? Now What will you do? When you electric field You would like to remove it at this point that brother, this
41:43 What is the electric field at the point? These so tell. The force that is being applied is that of the field It seems so because of the reason. Yes or no? Who Why was the force used? That field is his There is a reason behind it. If gravity is upon us It applies force. Gravity is the force on us If it appears, it is due to the gravitational field. It is from there. Which is the earth's own field. Somewhere far away, kilometers up. So She pulls things off. So the field's Because of this, forces come. Got it, right? So What has caused such a field? Force I. Now how will you remove the field? So he said brother The field will come out. The field will come out Divide this force by the test charge. Whoever you see this force on, Divide it. Whatever you are looking at the force on
42:28 Yes, divide it. Force / q knot Force / q knot. So this will come kq q not / r² q knot cut off from q knot. kq / r² arrived. So the electric field is What? Let me write it here. electric field is What? KQ / r² is a very cute little derivation. What should I call this derivation? define itself Let's do it like this. Define it, definition itself It is given in such a way that how much force is applied Is it happening? Divide by test charge. At which Divide the force you are seeing. Understanding Did you go? So, suppose someone already There is an electric field. Just look here. Value Suppose there is already an electric field and We brought some charge and kept it in it. Value
43:14 So, we applied q charge on it. Kept it. So tell me this field on this charge Will she use force or not? This field is Will force apply on charge yes or no? will impose Sir. Like the field applied force here By the way, I will put it here also. So this force knows How can I write 'hai'? We write it like this Can. See what e is? e happens Force/Charge. Yes sir, it happens. So the force from here can you not write q times e Can you? Take q and multiply by e Did it. hey which is e at this point and which Its charge is multiply both. The force will come out. So the force can be When the charge is applied inside the field, it It seems like qe. How much does it cost? will you remember This talk? How much does it cost? QE So the force exerted is Q times E charge
44:02 Multiply by electric field charge Multiplied by electric field is the Force Acting on This Charge Cleared What? and the electric field itself The value is KQ / R² if someone asks you. One How much field is applied at a distance r from the charge? Is it happening? That is KQ / R², got it? Good Look at one more thing here. is this Electric Field is not inversely proportional to r² What? Yes sir it is. This is also the inverse square She is following the law. Okay, right? And when its When you graph r, you get the value of E with r. When the graph is made with it, it falls like this It will happen. You understood why, right? Isn't it? A parabola will be formed, son. r² isn't it? So How to show you a falling parabola It will have to be done. The graph of R with E is given by
44:48 Showing it falling is for a point charge. Okay, right? For a source charge. It is clear talk? So we discussed a lot of things in this I have done about it. So let's ask an okay question. Let's see. He is saying calculate the Electric Field Strength Required to Just Support a Water Drop of Mass 10 Key Power - kg having a charge so much. a good The question is. What is Agen saying? is saying brother one by one It is a droplet of water. Ok? of water There is a drop. the drop of water on it mg is felt on the bottom. It will work, right? Brother Gravity will try to pull it down. For. But someone has stopped him upstairs. He asked, who is stopping you? Bole Electric The field has stopped. Look it is written
45:33 Electric field strength. She looks upwards. So it is a sure thing That there is such an electric field. Isn't it? Any action taken in this direction There is an electric field. up in space Perhaps she is stopping it by applying force towards it. Is. Something similar might be happening. Absolutely That's a good thing. Isn't it? So one thing to me Tell me, this upward force is applied by someone On q charge, isn't it qe? Say yes or no. Brother Electric Field Joe What will be the force applied on the charge? qe. So, that means both the forces are getting balanced. Isn't it?. That's why we are getting support. How Is he getting support? How it hangs They? Because the upward force is qe and The mg on the bottom balances among themselves Are happening. Are being cut. When will it be cut? When Will be equal. So understand that electric Force
46:20 And the gravitational forces are balancing out. Say yes or no. And if there is balance then Electric force is written as qe. Gravitational force is written as mg. Two. How much is the charge? 1.6 times 10 to the Power-19 Electric Field You Need to Remove Is. Correct? How much is the mass? Month is 10 months Take 10 to the power -3 and g, man. What Any problem? From here e will come out. Can you take it out? Unit of E is Newton per Coulomb it occurs. You must have understood that. Why? Because we write the electric field as Force/Charge. Look at this. Look at this what Do you write? what to the electric field Do you write? Force Divide by Charge. These Watch Force Divide by Charge. So by force The unit is formed from Newton and the unit from charge.
47:07 Coolam is made. So Coulomb on Newton. Newton But Coolum. What is the unit of electric field? Is it son? Coolum on Newton. The SI unit is Coolum on Newton. There is one more. They It is volt per meter. But in Chapter Two Why should I teach? He will read it in chapter two. Not now. The meter will also show one volt. To you. Like Coulomb is seen on Newton Meter is also available in volts but in seconds We will talk about it when it comes in the chapter. Correct? Let's move ahead. I already told you this I have given it, right? that whenever someone positive When it is charged, this is the force that is applied on it. It is caused by the electric field qe. Okay, right? And let's talk to this Suppose there is a negative charge, What will happen sir? If there is a minus charge, What will happen? Assume that the electric field
47:53 If a positive charge is placed, it will run away. Used to be. in the direction of the electric field You will run away brother. Oh, the electric field too. So is the vector. He also has a direction. So the direction of the force will also be the same. So Direction of Force of Electric Field The direction is the same. Now where is the force here? Will it work? But sir, here you have the force here. Will you show me? Shows force on negative charge I am behind. Why? Because he will come Brother. So the electric field is there. The electric field is there but the force is there It appears backwards in the negative. So Keep in mind that a negative charge If it happens, the force will follow. positive If there is a charge, the force will eat further. Correct Is? These things will be useful. Ok? negative Inversion of electric field on charge Force is required. if you if you any
48:38 If you keep the electron like this then it will be behind Will start running. If you place a proton, it will move forward. Will start running. Okay, right? So the force inside the electric field It works. Another big question, Important question. Let's see this also. is saying there is an electron that is Distance runs. How long did it last? 6 cm walked. When accelerated from rest. Accelerate from rest to 6 cm. walked. by an electric field of such strength of. Look at the Newton per Coulomb Here. It is said that calculate the time of How far does it take to travel? How long does it take to reach? Will I reach that distance? The Mass End charge of electron so and so here But they are given. So how do we do it? Let's see this. Look, you understand so much. is the electric field coming in And electrons are moving in it. So The electron must be moving in reverse like this.
49:24 What is the truth? What is the truth? This way Will the reverse work? Yes sir, that's how it will work. Correct. So where will the force be deployed on this? on the back It will take. And that force will be qe. Which you can also write as e. Isn't it? This too Just look. e because q electrons Charge is also written as e, isn't it brother? So It can also be written as e instead of q. Is. So we can write this as e. e times e What is small? Charge. What is big? Electric field. Ok? to see this too Let me feel it a little. Feeling like seeing this too You should come. Correct? Now it is saying that Brother, he has come from rest. Meaning here His speed was zero, man. Here his speed It was zero. Walk for some time and walk some distance
50:10 I have walked some distance. See how far it went He is saying 6 cm. It's gone. 6 cm Has walked a distance of. Ok? So 6 cm His velocity increased a bit as he walked. Will happen. What is the velocity right now? Zero. after It must have increased. saying how much time I have travelled. What are these givens? Just look at it once. saying initial Velocity is zero. Displacement is given 6 cm But you divide it by 100. So it has come to 0.6 meters. So it is right? Displacement also came. Ok? Good We know that the force is e. But what about the force? Can I write ma? Tell me friend. Can I write ma instead of f? Am? Yes sir, you can write. So what from here? Should I remove the acceleration? e in e / m *
50:57 That's correct. Put e how much is it? e What happens? Charge of n electron. They How much is it? This much. What is 1.6 * 10 to the power of -19 mass? These Raha 9 * 10 to the Power -31 and Electric What is the value of the field brother? Here it is, Di 2 * 10 to the power of 4 is 2 * 10 to the power of 4. is acceleration. This is the full acceleration. Do you understand the matter To? Ok? And what have you been asked? How much time will it take to arrive as asked by you? Here? Tell me one thing. S has happened, U has given Yes, A is given, T is asked. Son We will put S = UT + 1/2 AT² Yes and no. and S how much given Is? 0.6
51:43 The UT part will become zero. + 1/2 Where is the acceleration? This is complete. This whole You put the acceleration here and look at the t² here. Will come out from. Isn't it? You can write it like this yes. 0.6 * 2 right? Divide by a = t² then From here you will take it out by under routing. Tell me what is the problem? Did you understand? How Do you want to find time? ok sir. Can you understand? How Do you want to find time? If you cannot come I have brought the calculations. [laughter] Okay? Do not panic. Ok. If you did not understand then I have brought the calculations. Ok. s look 0.6 Okay, right? 06 He will come, friend. Yes. Only 0.06 will come. This is 0
52:30 06 The same will come here as well, 0.06 Okay, after that you see this s = utf² It is installed. You can remove it from here under By rooting. Okay, right? Approximate answer also You can write. no such problem Not there. Okay, right? Don't worry. Correct Is? You understand the logic. What is logic? Come On the properties of electric field lines Let's go. All properties one by one I understand. All of it is important. Come see. saying the lines of force are Continuous smooth cubes without any Breaks. There are no brakes. Any There will be no breakage in the middle. If electric If the field line is going like this then it is completely Will go. in between like this like this It does not move in pieces. She is the whole
53:15 It will work. Good, you must have understood it first. To you. The other is saying The Lines of Force start at the positive charge and at the Negative. Always look out for the positive removes the electric field and Always brings towards the negative. This one Property is very important. Plus from Always plus outside and minus inside Okay, right? saying they can't form closed Loops. They will not be able to create a closed loop Because it came out of plus and went into minus She will go and get terminated. as the bus moves Isn't it that you moved from one place to another? It got terminated. Now, now, holiday, now, driver Also a holiday. Now tomorrow morning will come and vice versa Will run it. Isn't it? So this is the scene. Understanding Did you go? That brother, he moved from one place to another. But it got terminated, go home on leave. Understand? If there is a single charge then the Lines of force will start and end at Infinity. If a charge is alone,
54:01 Meaning, he alone is positive. think negative It doesn't exist. Then where will it end? These? So they say it will go till infinity. Where Will it end there? It will go to infinity. only then So that graph did not touch zero. Happened. Isn't it? The graph of E with R was It kept going on like this. He will not touch anytime. Isn't it? Isn't it? It doesn't touch down It can because it goes to infinity. Correct Is? The electric field goes to infinity Is. Third look. saying the tangent to a Line of force at any point gives the direction of the electric field at that Point. What does it mean? anyone is saying Suppose the electric field is going You can draw a tangent on it anywhere. As The electric field is gone, isn't it? you anywhere Take a tangent. Like this tangent line Took. It happens by touching this point, right? Brother Tangent. This is the point. touches this The tangent will be like this. So you have electric
54:46 You will get the direction of the field. from him you You will also be able to find out the direction of the force. Is No? in the direction of the electric field F is applied on any positive charge. you here But think about it, if you take a tangent here. Find the direction of the electric field here. You will take it. Got it, right? So by drawing a tangent you Finding the direction of the electric field You will find it. What will happen with that? Brother, you force him Will be able to take it out. Because the direction in which The electric field goes in the same direction Positive charge also moves in it. That is, on that The same force is applied. Ok? further saying that no two lines ever intersect Will do. Never intersect each other. and its What is the reason given? gave the reason for this It has happened that brothers will again become two tangents. For example, suppose there are two lines They are intersecting. Okay, right? So
55:32 There will be two tangents at the same point. And If there are two tangents then it means two each Directions will be established. So where will the charge go? In which direction will it go? Then this is Isn't there a problem brother? Tangent to direction He gives it, right? So where should I keep the charge here? Will you go? Then will he go here or here? So You don't understand the point, right? So say that saying that if they intersect then there will Be No There Will Be to Tangent at the Point of intersection and hence two directions of the electric field at the same time which It is not possible. same point at the same time But the field cannot be in two directions. There cannot be force. That's why I told you this That's going to be brother intersection never Will do. Okay, right? Two field lines are always They do not cross each other. Ok? Ahead The Lines of Force Have a Tendency to Expand literally. This is also a property written It happened that brother, when positive positive charge
56:19 If they come in front of you, she tries one. To run away from the other. So this expands She pulls it backwards. See. So as to exert a lateral pressure on the Neighboring lines of force. This Explains Repulsion between the two similar charges. Similarly, when one positive becomes negative So in a way they get suppressed, they get bound. plus plus one will expand laterally and Shrink in a plus-minus way Will do. You can understand this. The relative closeness of the lines of Force gives a measure of the strength of the Electro. Meaning the denser the field The more it happens, the stronger the field will be. Like look here, look at this area. Isn't the field strung? So here it is But what are we going to say about what the field is? It is strong. Got it, right? wherever this
57:05 If it is coming nearby then we will call it field It is strong. And what is there in this area? There is a week field here in this area. Understanding Did you go? This will be called strong field. This will be called strong field. will say it Weak Field. Ok? When the gapping is high If she goes in line then she is weak. when the lines If they are close then they are strong. Excellent. And This is a uniform field in which the line The spacing remains the same. Look at the line The spacing is the same. Same line spacing. here too, here too, here too, here too, here Too. If there is same line spacing then we say Uniform field. What do you say? Uniform field. One more important thing. But the discussion of Whatever is there, there is more in Chapter Two. in the forest There is no discussion. But listen anyway. Any Any electric field inside the conductor It never happens.
57:50 The reason behind this is that when from outside If the field comes then it vomits inside also. The field starts running. Now why this To know what does Chapter Two do, you need to
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