Magnetic Effects of Electric Current in 20 Minutes🔥| Class 10th | Rapid Revision | Prashant Kirad

0:00 So hi everyone I am your very own Prashant Bhaiya and I have brought the next chapter of Rapid Revision which is Magnetic Effect of Current. Remember this chapter Magnetic Effect of Current is a very important chapter. Children tend to underestimate it but today we are going to do the complete revision of this chapter within 15 to 20 minutes. If you want to understand this chapter in detail and read it in detail, I have given a one and half hour long video in detail so go and read it, the link is in the description but today we are going to do the revision and that too in just 15 to 20 minutes. So let's start quickly. First of all let's see how magnetism is presented in nature. So look there are three types of magnetism in our nature. First of all the earth has its own magnetism. This earth rotates and because of that it has its

0:45 own magnetism. Apart from that no metals are found inside the earth. Those who have magnetic properties, which metals are nickel, cobalt, all of them have their own magnetic properties and there is another way by which magnetic effect can be generated, that is with the help of moving charge, that is, if current is flowing, then magnetic effect will be seen and we have to read this chapter on this, now who came to know about this, there was a scientist whose name was Christian Ostard Ostard Bhaiya ji came and Ostard Bhaiya ji said, hey, he did an experiment, what did he do in the experiment, he took a circuit, okay, electric current is passing through it, he kept a magnetic needle near it and as soon as the current was passed, there was a

1:30 deflection inside the magnetic needle, the magnetic needle started moving, then Ostard Bhaiya said, hey, magic, but it was not magic, what was it that when a current flows, what does it create, it generates a magnetic field around itself, due to which this compass started moving, who did it We have to remember the name of the scientist, let's move ahead. Now first of all, let's talk about what a bar magnet is. Look, a bar magnet is nothing, it is a magnet that looks like this. You must be seeing it here. I hope this is your bar magnet and we call this magnet a horseshoe magnet. Now look, every magnet has two parts. One is the north pole and the other is the south pole. We have read in the lower classes that what happens is that the same poles repel and the opposite poles attract. We have already read this. Let's look at some more properties of a bar magnet. Now another

2:16 important property of this is that if we break a bar magnet from the middle, it will always have only two poles. For example, imagine, there was a bar magnet called North South. I broke it. Do you know what will happen? Now, in this smaller piece also, it will become North South. And what will happen in this piece also, it will become North and South, that is, there will always be two poles inside a bar magnet? Okay, these are some of its features. There are some simple features of a bar magnet. I hope everyone knows this now. Let's talk about magnetic field. What is a very important magnetic field? For example, imagine how far are you standing from your mother so that your mother can slap you. So that is your mother's field. If you go too far, will you be able to slap? No, at that time a flying slipper can come but a slap cannot come. Similarly, every magnet has its own field. The area within which it can make the other person

3:04 feel its force of attraction is called magnetic field. So remember the area around the magnet in which the effect of magnetism is felt, where magnetism can be felt. The next thing is magnetic field of lines. What are these? They are nothing. They are imaginary lines, aren't they? They are imaginary lines which tell about your magnetic field. We call them magnetic field of lines. Now an important thing is the properties of magnetic field of line. And son, it is certain that one question will come every time. What are the properties? It is a very simple property. The first property is magnetic field of line north. It starts from the north and goes towards the south. I will explain it to you with the help of a diagram. Look, the magnetic field lines will always start from the north and will go towards the south. Outside the magnet, inside the magnet, it will go from south to north, that is, the magnetic field lines form a close

3:50 loop. Look, a loop is being formed. A loop is being formed. Alright, what is the next property? The next property is that where the magnetic field lines are close or close, the strength of the magnetic field will be more there, like at the poles, look at how close they are, you can see at the poles, how close they are, so what is it here, the strength of the magnetic field will be more here, whereas it will be less in these directions. Alright, now you have understood this thing. Apart from that, if we draw a tangent on any magnetic field lines, draw a straight line like this, then what will it tell us? It will tell the direction of the magnetic field. What is the next property? No two magnetic field lines can intersect each other. Why can't they intersect? Because brother, imagine? Do this, if two field lines intersect, then brother, there is

4:37 one direction here at this point, one direction here, can there be two directions of magnetic field at one point, there can be two paths, but they cannot be, because of this, magnetic field lines never intersect, these four-five are its important features, important properties, remember these, you will definitely get this question, you are asked about properties every time, let's move ahead, what is next, Maxwell right hand thumb rule, now what is Maxwell right hand therm rule, look son, now we have come to know that a current carrying wire generates magnetic field, but what is its direction, so what does Maxwell thumb rule say that if we point our thumb in the direction of current, okay, and we curl our fingers around it, can you see son, can you see, if we curl our fingers, then the direction in which we curl our fingers, son, the

5:22 direction in which we are curling our fingers, that is the direction Let us understand from the example of whose magnetic field it will be. Imagine there is a wire, this is the wire, it is carrying current in this direction, so I will keep my thumb like this, okay, after that I will curl my fingers, that is, how will the magnetic field lines be like, they will be rotating like this, and we call this concentric circles, concentric circles, so that means the direction of the magnetic field inside a straight wire, how is it, it is in the form of concentric circles, okay, I hope you have understood this, understand the next thing, I will tell you one more important thing, if imagine here, imagine the wire is like this, then how will we point the thumb, we will point the thumb here, we will point the thumb downwards and I will curl my finger like this,

6:07 I will curl my finger like this, are you able to understand, that is, if you can imagine a little son, I will also show you on the next page, if my, see son, if my wire is like this, okay, it is carrying current in this direction So see how it is round round round which direction is it son which direction is it anti clockwise which one is anticlockwise whereas if my wire is downwards then now make it now make it see which direction is it son now which direction is it clockwise direction so remember whenever my wire is in upward direction then what will be the direction of the magnetic field anticlockwise whereas if it is downward then what will be the direction of the magnetic field clockwise and question on this has already been asked in MCQ

6:53 so remember anticlockwise clockwise don't get confused it's a very simple concept okay if it is above anticlockwise if it is below then what is clockwise keep this much in mind now an experiment was also done on this how was this thing found out with the help of experiment what did the scientist do here took a paper and on that paper there were many small metallic You have put small pieces, right? Your iron pieces have put them in. Now, when current was passed through it, after a while you saw that the iron pieces got formed in the shape of a concentric circle, as you can see here, round, round, round, they got formed in this shape. Then the scientist understood what a straight current carrying wire makes. It makes concentric circles around itself. You have to remember this thing. It is very very important.

7:39 Let us move ahead. What is our next concept? Our magnetic field of lines due to current carrying loop. See, imagine that we were talking about a straight wire. Now, if I talk about a loop, what is a loop? Imagine a circle. If current is being carried inside a circle, then how would the magnetic field around it be? It is a very important diagram, son. You will have to remember this diagram. See, if you will see inside this small part, inside this small part, what is the direction of the current, the current is moving like this. The current is moving like this. All right, then we will use the rule. We will apply the thumb rule and we will see, it is a circle, similarly here the current is like this, we will see, it is a circle, so how would the magnetic field be at both the ends, it would be a circle, okay, but the thing to understand here is that at the center point of a circular loop, the direction of the

8:26 magnetic field in the center point is straight, it is straight, that is, if this is a loop, son, we have to imagine, there is a loop, then there will be a round round round round magnetic field at its ends, but so the center is inside it, the magnetic field would be like this, it would be going straight inwards, can you see straight, yes, so this is a very important concept and this diagram is also asked again and again that what is the direction of the magnetic field inside a current carrying loop, so you make this diagram and remember how it is at the center, it is becoming absolutely straight, now let's talk further, solenoids are nothing, right now we were talking about a loop, if we rotate a lot of loops, that is, take a wire, take a wire and keep rotating it, keep rotating it Keep rotating it, keep rotating it, what does it make, it

9:14 makes loops of solenoids, so we call it solenoids. Now when I let the current pass, tell me one thing, inside a loop, suppose the current is going like this, okay, inside a loop, what is the direction of the magnetic field, how is it in the center, towards the inside, right? There are so many loops here, that means the direction of the magnetic field here will be completely straight, so remember what is the direction of the solenoids field, it is completely straight, right? And outside it, how is it, outside, so you can see, right? Outside, you can see, so it behaves like a solenoid, that means what used to be a bar magnet, the north pole, the south pole, the magnetic field of line used to come out from the north, used to go inside the south, okay, and

10:00 what used to be inside the magnet, inside the magnet, it used to go from south to north, yes or no, I remember, it is shining very well, that means it is the same story, so solenoids as a bar magnet, from north to south, inside from south to north, but the difference is that the bar magnet is a permanent magnet Yes, but this is not a permanent magnet. What will happen if I remove the battery from here? The circuit ends as soon as the battery is removed. If the circuit ends, its magnetic power also ends. So remember, remember, I have generated a magnet once with the help of solenoids. That is what we call solenoids. And remember, this is the concept of an electromagnet. What is an electromagnet? You must have seen in movies that big cranes are used to

10:48 stick to any object. You must have seen big vehicles coming and sticking to any object. What is that? It is a type of electromagnet, that is, a magnet that is running with the help of electricity. We call it an electromagnet. And it is nothing. The strength of the magnetic field of the solenoids will depend on many things. The first thing is the number of turns. Remember, how many turns have you made inside the coil, that is, how much the coil is twisted. The more the turns, the more will be the magnetic field. Next, let's see the amount of current. The higher the current, the higher will be the strength of the magnetic field. What's next? The radius of the coil. The radius of the coil

11:34 also depends on the strength of your magnetic field. What's next? The material of the core of the solenoids. We put soft iron so that it can show its magnetic properties. So the core, the material you are putting inside is also very important. So remember, these are the four factors with the help of which we determine the strength of the magnetic field. Okay, you have to remember these four factors. A question was also asked in the board that what are the factors on which it depends. So you have to remember these four factors. Done, it's clear till here. Now let's see a difference between an electromagnet and a permanent magnet. The first difference is that an electromagnet can change its magnetic strength. How can it change by increasing the current, but for a permanent magnet. The

12:20 strength cannot change nor can an electromagnet change its direction how can it change if I change the direction of the current its direction will also change but a permanent magnet cannot change its direction okay so there are four-five such points written here you can also see strength changes with current looses magnetism when current stops as soon as the current is stopped what will happen its magnetism will stop apart from that it needs electricity to stay magnetic electricity is needed it needs electricity poles can be switched if we change the current then the north south poles will also change whereas nothing of this kind happens in these these are some three-four differences remember which one is inside your electromagnet and permanent magnet let us see the next concept forces on current carrying conductor now a new theory came to the mind of the scientist he thought that

13:07 look if we take a current carrying wire and hang it okay there is a magnet near it then will they apply force between themselves and both of them applied force between themselves and that We were also taught to find the direction of force with the help of Fleming Left Hand Rule. What does the Fleming Left Hand Rule say, son? Understand it carefully. The statement is very important. It is asked repeatedly in the paper. It says that we have to keep our thumb, index finger and middle finger at 90° where our thumb tells us the direction of force. Our index finger tells us the direction of the magnetic field and this middle finger tells the direction of the current. But Bhaiya, how will you remember, I said, I will tell you the trick. Don't take tension. What is the trick? First your papa, i.e.

13:54 father. Then your mummy, i.e. mother. Then you, i.e. children. Father, i.e. force. Mother, i.e. magnetic field. Children, i.e. current. Now that you have remembered it, you won't forget it now. So, what do we do with the help of these three things? With their help, we can easily find out the direction of the force. So, understand carefully what the Fleming Left Hand Rule says. Fleming Left Hand Rule says that if we stretch all three perpendicularly, then the thumb will be No, it will tell us what is the direction of the force, that is, if I am representing the direction of the current with this and I am representing the direction of the magnetic field with the index finger, then my thumb will tell what will be the direction of the force. First of all, this statement is very important, apart from that, a lot of numericals are also asked in it. Bhaiya,

14:40 you tell me how numericals are asked, then I will get you through a couple of numericals. Look, remember one point, whenever you see cross cross cross cross, what does it mean that the magnetic field is inwards, but if you see dot dot dot dot like this, then remember that the magnetic field is outwards, isn't it? This is a simple thing, you are already reading, you must know, okay, now solve this question, if the magnetic field is inwards, okay, if the direction of the current is this, then where will the force be applied, son, let's solve it once, make your fingers like this, quickly, is n't it? And if we solve this, then you You can see this is the magnetic field, what was the magnetic field, put the index finger inside and move the middle finger upwards, where is the thumb coming, the thumb is coming in this direction, so the direction of the force will be the same, son, this is the same for all, let's solve this question, now

15:26 see in this what is the magnetic field inside and the direction of the current, so where is the thumb upward, where will our force be applied, the force will be applied upward, so there are many such questions, now if we move on to its level two, then a question is repeatedly asked, remember about alpha particle and electron, remember we are taking the direction of current here, to confuse you in the question, it will be said that an electron is moving, what is an electron, son, there is a negative charge, the direction of the electron, the direction of the current is opposite to it, so if in the question you have been given electron, and the direction of this is given, then you actually know which direction Why do you have to take this one because the direction of current is opposite as compared to electrons, you have to remember this thing, so now take this direction and solve this question quickly,

16:12 as you can see where is the magnetic field inside, where is the direction of current, the direction of current is towards this side, so where is your thumb pointing, thumb is pointing downward, so that means the force will be towards the bottom, right? And a similar question comes in alpha particle, there is nothing to do in alpha particle, alpha particle is a type of positive particle, done, let's understand everything till here, you can practice many such numericals from different books, now we move towards the last topic which is domestic circuit, son, domestic circuit is of two types, isn't it? The electricity that is coming inside our homes comes inside AC, which is your alternating current, apart from that there is another thing which is your direct current, which is your It happens inside batteries. Now questions can definitely be asked on its difference. Remember the differences. Look, what is alternating current? Basically,

16:57 alternating current is yours. To travel long distances, the current here keeps changing its direction. Sometimes it goes here, sometimes it goes there. It keeps changing its direction. And what is its function? AC can travel safely for long distances, whereas DC cannot travel long distances. Let us see the next point, the frequency is 50 and 60 Hz. In India, it is 50 Hz and in other countries, it is 60 Hz. What does 50 Hz and 60 Hz mean? It means that the movement that is happening, son, what is happening? 50 movements are happening within one second. It means 50 Hz. Okay son, so it is 50 and 60 Hz depending on the country. There is no frequency here. The next current of DC is zero frequency. Direction reverse periodic current keeps changing its direction there is no change in direction next it is cheaper

17:44 than DC generation it is a little cheaper that's why all the electric wires that come to your house come on AC whereas this is a little expensive it is used inside batteries okay this difference was important for you now the next point that remains is what are your wires look basically there are three types of wires that come inside your house isn't it one is your live wire one is neutral wire and there is another wire which we call green wire now let me tell you about it which we also call earth wire so basically with the help of this diagram I will explain to you live wires are always red coloured wires which carry current okay and your neutral wires are always black coloured remember what is the colour its colour is black and its colour is red okay so the red ones carry the current the black

18:31 ones take the current back Let's bring it. Okay, here if we see, a simple circuit of your house is given. The live wire is here. This is your electrical meter, which will tell you how much you have to pay. What is your distribution? Different wires will go here. Here is your appliance. You can see the green wire on the appliance and it is connected to the green wire. What is green wire? This is green wire. Earth wire. What does earth wire do? Basically, all your appliances leak some charge. Charges get leaked. So, when the charges leak, if you touch them, you will get an electric shock. To protect us from the shock of that electric current, we get it earthed. That is, all our appliances go underground. So, all the excess current, that extra current, where does it go? It goes to the ground. By the help of earth wire,

19:16 you can also read here what it is. Its color is green. Its main job is to take the leaked charge to the ground so that we can avoid electric shock. This is the job of your green wire. So, this is clear to you. Earth wire, live wire, neutral wire. I hope this is absolutely clear. Now, let us move towards the next point, which is short circuit, overloading and electrical fuse. Let us understand what a short circuit is by a simple example. Imagine, you had to light a bulb. You had to light this bulb, one is your live wire and one is your neutral wire, okay now imagine what happened by mistake that the live and neutral wires got mixed up, they touched each other, now as soon as they touched each other, the current got a short path, now the current will not go from here, now what will your current do, it will try to go from here only,

20:02 remember in this condition the resistance becomes zero and your current becomes infinity, it becomes very high and a condition is asked when does a short circuit happen, when the resistance becomes almost zero and the current becomes infinity, what will happen in that condition, son, in that condition a fire can start, a spark can happen whenever your live and neutral wires collide with each other and that condition is called short circuit, next comes overloading, how does overloading happen, if you have put many plugs in a switch, you are thinking that I can run the AC with a single switch If I turn on the refrigerator, what will happen is that a lot of heat will be generated, so much heat will be generated that your wires might melt and that is called overloading. Remember if the total current drawn through the wire by the appliance connected to it exceeds the

20:48 safety limit, whatever is its safety limit, if you are drawing more current than that, then what will happen, your wire might melt. Last comes the electrical fuse. Now see, we have also read about electrical fuse in the electricity chapter. Basically, what is inside it is very simple. A fuse is fitted inside the meter outside you. What is its function? If more voltage comes, it melts quickly. Its melting point is low. It melts, so what happens is that it breaks your circuit. What is the benefit of breaking the circuit? If more voltage reaches your appliances, then your appliances might get damaged. So, what protects you from that? An electrical fuse protects you from that. So remember what is an electrical fuse? It has a low melting point. What does it do? It breaks due to the heat caused by over voltage. Or high load whenever high load high voltage comes it breaks it avoids

21:34 short circuit and failure, isn't it, this helps you to avoid short circuit, so I have told you all three and right here itself our simple chapter ends and here is your question for today, solve it quickly, it is numerical and tell me in the comment, on this note I hope you liked the video, which chapter do you want next, do tell in the comment, my name is Prashant, see you in the next video, take care, love you all