POWER SYSTEM TOP 50 MCQ'S / PSPCL ALM , JE , ASSA #pspclalmexampreparation #pspclalmnewupdate

Added: 2026-05-31

[00:00:18]Hello and good evening everyone. Good evening everyone. Sat Sri Akal Ji. Let's start the class. First of all, share the class with everyone. Because after a long time, we are coming live and share the class with everyone. Sat Sri Akal Ji.

[00:00:42]In today's class, we will do the top MCQs of power systems at the level of both ELM and JAI. Okay.

[00:00:48]Look, in this class, there are some power system topics and we will do some power system topics in the next classes because we cannot do all the power system topics in one class.

[00:01:00]So like here we will learn about transmission lines, we will learn about sag, we will learn about corona effect, front effect, power factor, we will learn about underground cables. So, in this class, we will cover all these things with theory and MCQs, so if you have studied power systems, then well and good, I will explain everything to you with clarity. Even if you haven't read it, you can still watch this class because the way I explain it will help you understand. The syllabus is almost done. Okay, there is not much syllabus left. The syllabus is almost done and before starting the class, there is some more information for you, such as whether you are doing IT or are doing it and if your colleagues, relatives, friends with ITI also want to do IT, then they also have IT admissions going on. Now see, you will find a specialty in something or the other every time. If you get an ITI from us, you will get a stipend and a scholarship. The more fees you pay, the more scholarship you will get. The fees will also be the lowest.

[00:02:09]And the main thing is that if you get admitted, the preparation you need will also be done for free. Preparation for ITI and upcoming ITI/ITIA exams will also be done free of cost and there will be a scholarship and you can confirm your seat by contacting this number and there will also be a dharna on a certain date, Patiala is fine. So one more thing, everyone should reach the dharna too, because it is a dharna and everyone should reach the dharna too because only then will your reading be of any use. Okay, we will also join you, but the responsibility is yours, we cannot show the gathering of people to reach the dharna.

[00:02:46]You can show up for the gathering, okay, we can support you, and everyone has to definitely come to the protest too.

[00:02:52]Okay, whether you will come or not, we will all meet at the protest. Then, yes, electronics are left, Jasviro, we will do electronics.

[00:03:06]Okay, let's start the class. Let's move on to the first lesson.

[00:03:11]What is written in the first lesson?

[00:03:14]What are the benefits of high voltage operation, that is, the advantage of transmitting at high voltage?

[00:03:18]We know when we talk about transmission, right?

[00:03:20]When we talk about transmission, we know that we transfer power at 400 kV, 765 kV, 220 kV, right, 132 kV, we supply and send power at such high voltage. So what are the benefits of sending power at high voltage? I am asking you, " Star" means that the current is reduced, it reduces the voltage drop, the power loss is reduced, or all of these. Tell me the right answer.

[00:03:53]Okay, tell me the right answer. Tell me the right answer. Now, you will have the right answer. Look at all of these.

[00:03:58]Now, understand one thing carefully.

[00:04:00]When you are sending power, you are sending it by increasing the voltage.

[00:04:05]What are you doing to the voltage? You are increasing the voltage. Okay, now look, if you increase the voltage, what will happen to the current in your line? It will decrease. If the current in the line decreases, then the losses that will occur will also decrease. So, one point has been made here that when you increase the voltage, the losses in your transmission line will decrease. Then if you increase the voltage, the current will decrease. If the current decreases, the power factor will increase. Then one more thing will be clear that when you increase the voltage, the power factor will also improve. Let's move on to the transmission line. If you increase the voltage, your current will decrease.

[00:04:45]If your current decreases, the size of the conductor will also decrease. See, the size of the conductor will also decrease. That is, we can say that the area of ​​the conductor will also decrease. And the third point has also been cleared.

[00:04:56]When you increase the voltage, the area of ​​the conductor will decrease. If the area of ​​the conductor decreases, then the cost of the conductor will also decrease. That is, the cost of the conductor will also decrease. This means that when you increase the voltage, you get to see these three or four advantages. First, your losses decrease. The power factor of the conductor increases. The area of ​​the conductor decreases. And the cost of the conductor also decreases. So, all these things are what we get when We send power to high voltage.

[00:05:25]Okay, yes, it's cleared.

[00:05:31]Bagjit Singh, his admission will be done.

[00:05:33]You can contact the number. Yes, contact the number. Admission will be done. Let's design the feeder mainly from the perspective of the dash.

[00:05:41]Okay, what are we talking about here? We're talking about feeders.

[00:05:45]Now you answer this question, then I will explain this question to you in such a good way that from today onwards you will never make any mistake between feeder and distributor.

[00:05:53]Answer this question first. The feeder is designed primarily from the perspective of the dash.

[00:06:00]Based on the voltage drop, the current capacity, number of tappings or frequency of the system, yes, Jasvir, your topper will be the topper, yes, yes, please answer this, let's all understand, first share it with the class, then I will explain to you today, today I will bring you all something fun to do in the power system, let's understand, this is your substation, your supply from the substation, from the substation which is your 11 kV supply, right, look at the supply of 11, R phase, phase, and phase, 11V supply, we have packed a complete type in the conductor and sent it, look at the transformer, this will be your distribution transformer, which transformer is this distribution transformer, then look at the distribution transformer, there are three ways, R phase, Y phase, B phase, how much voltage is coming from this transformer, this 11V supply is coming, right, you will not find the photo anywhere.

[00:07:17]I have designed it specially for you from AI, so look at the transformer, it is getting 11V supply. Look at the wire coming from the substation. Look at the 11th wire coming from the substation. The three wires coming from the RV are 11th.

[00:07:31]We call this the feeder. Pay attention.

[00:07:34]Everyone understood what a feeder means. Look, a feeder has three wires and how many kV of supply is there? If it is a 11V supply, then a feeder is called a single wire. It is called a supply system.

[00:07:44]What is a feeder? The wires that come from the substation to the distribution transformer are called feeders. Okay, good, after that, look, there will be four types of wires coming out of the transformer, R phase, Y phase, B phase and a neutral coming out to you. Okay, so we call this a four-wire system. Four-wire system, look at these four types. They will be above your houses.

[00:08:07]Look at what four types of wires go above your houses. Look, the four wires that are there are we call distributors. What do we call distributors? Now that you understand, you know the difference between feeder and distributor.

[00:08:21]What is feeder? The 11th one, which is the input of the transformer, we call it feeder and the four wires that come out of the transformer in four types, which go towards your houses, we call it distributors. Okay, good, after that, you should keep one thing in mind, when we take the supply, we will take the supply from here, not one phase from here and the neutral from here. We will connect one phase here and the neutral here. Okay, so the wires that we take out from here, we tap, we call it the service main. What do we have? The service mains, the service mains from which we tap, we call it the service mains.

[00:08:55]Okay, look, the feeder is designed based on the current capacity.

[00:09:01]Remember, the wire is not designed based on the current capacity. And the distributor, which has four types of distributors, look at these four types. These four types are here. We have to send voltage to the house as well. We have to send voltage to the house as well. We have to send voltage to all the houses.

[00:09:19]So the voltage should be equal in all the houses.

[00:09:21]Now, if someone is doing it at the end, we will give him a little bit of voltage. We will give you the same voltage.

[00:09:28]So, the distributor is not designed based on the voltage rating.

[00:09:32]Based on capacity, the distributor will be based on your voltage capacity and the feeder will be based on your current capacity.

[00:09:40]Tell me, did you understand? Did you understand? Everyone, did you understand?

[00:09:43]Everyone, now you don't forget, now you don't forget this thing, quickly tell me, everyone, you understand, let's move on.

[00:09:52]Then let's say, what are three phases and one neutral, which we call a three-phase four-wire system? What is a three- phase four-wire system? Then see what distributors are. Distributors have three- phase four-wire systems.

[00:10:28]Remember, and what three-phase three-wire systems will be?

[00:10:31]See, a three-phase three-wire system has a feeder, they call it a feeder.

[00:10:36]In transmission, we use a three-phase three- wire system.

[00:10:40]Right, in the feeder, in transmission. And where do we use a three-phase four-wire system?

[00:10:45]We use it in distribution, in secondary distribution. Right, right, no, don't forget, Guru ji. Okay, yes, let's go. It's clear, everyone, go ahead. Let's go and see, let's go and see, look at what is made here too, those that are coming in three ways have feeders, okay, so those that come in four ways have distributors, all of them have distributors, so look here, if we want to make a single phase supply, what will we do to make a single phase supply? We will take out one phase and along with a neutral, we will have a single supply of 240 volts.

[00:11:22]If you want to make three phases from here, then remove one red phase, one yellow phase, one blue phase, and you will have a three-phase supply of 440 volts or 415 volts.

[00:11:32]Okay, let's see everyone, which of the following causes permanent damage to the insulator in the transmission line? Okay, the following is the permanent damage of the fuse.

[00:11:47]Which of the following causes permanent damage to the insulator?

[00:11:52]Permanent damage means that the insulator itself gets damaged. Okay, the insulator itself gets damaged. Permanent damage.

[00:12:01]We call this permanent damage.

[00:12:02]Which of these four can cause permanent damage to the insulator? Flashover, puncture, dry band, arcing or corona discharge.

[00:12:15]Sir, if someone's house is far from the transformer, there will be a difference in the voltage. No, it doesn't happen.

[00:12:20]Bagjit Singh. It doesn't happen.

[00:12:23]If the house is far from the transformer, there will be no difference in the voltage because the distributor would not be connected in parallel and the voltage in parallel would remain the same. There will be a little difference, but it won't be that much difference. Okay, let's assume a little more, there will be a difference of two-three%.

[00:12:37]But it won't be more than this.

[00:12:40]Yes, look, you have one of these insulators.

[00:12:43]Okay, you have an insulator.

[00:12:47]Look, if voltage is passing over the insulator, sorry, current is flowing over the insulator.

[00:12:51]Current is flowing over it.

[00:12:54]We call it flashover. Flashover voltage. If it is passing over it, look, the insulator is not damaged due to flashover voltage.

[00:13:02]But when your motorcycle tire gets punctured, okay, the tube etc. bursts, then the tube gets new water. Or it happens with the insulator. If it bursts in the middle of the insulator, that is, there is such a voltage that passes through the insulator. So what happened to your insulator here? The insulator got punctured. What happened to your insulator? It got punched.

[00:13:21]Being a punched insulator, the insulator gets completely damaged. What will happen to you?

[00:13:30]Remember, the punch that you get is more than that.

[00:13:38]Sat Sri Akal Sandeep.

[00:13:40]Okay, punch everyone. Yes, let's move on to the next question. Well, in any case, what will happen if the height of the transmission tower is increased? In any case, the height of the transmission tower is increased. Look, you have a transmission tower. Okay, you have a transmission tower. So, if you increase the height of the transmission tower, that is, if you raise the transmission tower, then what will be the effect of raising it? I am asking about the inductance of the line.

[00:14:10]Look, the line capacitance and inductance will not change. Line inductance.

[00:14:19]Line capacitance and inductance will decrease. That is, both will decrease. Line capacitance will decrease and line inductance will increase.

[00:14:31]Look, it is a simple thing. Pay attention to this.

[00:14:36]I will explain to you the weight second diagram. Look, look, you have a transmission tower, look, look, look, how clearly you can see it in the picture, look, this transmission tower, look, look, you have a transmission tower, look, that whatever current flows through the R phase, the same current will flow through the H phase, and the same current will flow through the H phase, look, when the current flows, look, a magnetic field is being formed around the wire, what is being formed around the wire, a magnetic field is being formed, because of this, its own reactance is being created, what is being created, reactance is being created, so the magnetic field that is being formed round round round round, no, this magnetic field is being formed near you, then what will be created, reactance will be created, look, the second thing, look, look, here you have a conductor and here is the ground below, look, here is the conductor and here is the ground, between the conductor and the ground, see, the capacitors are being formed, what is this here? If capacitance is formed, then look at the inductance in the transmission line. You have understood how inductance is formed. When a magnetic field is formed here, and between the line and the earth, capacitance will also be formed here. The capacitor is formed here.

[00:15:51]Okay, let's assume that you increase the height of the tower.

[00:15:53]Look at the increase in the height of the tower. Let's assume that your R phase has come here.

[00:15:58]If your R phase has come here, then the distance between this phase and this ground will increase. What will happen to the distance between them? It will increase. If the distance increases, what will happen to your capacitor? Then it will decrease.

[00:16:12]Okay, if the distance increases, then what will happen to the capacitor? It will decrease. But see, there will be no effect on the inductance because we have increased the length of the wire a little.

[00:16:21]We have increased the height of the tower.

[00:16:23]Neither then, now see, sound is coming. Now, sound.

[00:17:33]Now, sound. The distance between my conductor and the ground has increased.

[00:17:47]But with this, there will be no effect on the reactance.

[00:17:50]So, the capacitor has decreased. But there will be no effect on the reactance. That's why you will have a right-handed head here.

[00:17:59]Jasvir, which will be the inductance change.

[00:18:02]The change will be the reason for the wire. The reason for the wire is okay. Come on, look now. Look, it will be cleared now. Okay. Okay. Okay. Come on, look, what was I saying here?

[00:21:26]Look, the bedding is done, the armoring is done, and the serving is done. Okay. Now pay attention here.

[00:21:32]They asked, what is the bedding made of? If we look here, what will this conductor be made of?

[00:21:38]Or will it be aluminum or copper? Will it be a standard conductor? Will it be aluminum or copper?

[00:21:46]Okay, after that, see what the insulation will be made of. See if your insulation can be made of PVC. It can be PVC. It can be polymer. It can be PVC polymer. It can be impregnated paper. It can be impregnated paper. It can be XLPE. It can be cross-linked polyethylene.

[00:22:05]With all these things, your insulation can be made of whatever material you want. Then came the metallic sheet. What does the metallic sheet do? It doesn't absorb moisture from here. What does this metallic sheet do? It absorbs moisture. What is it made of? It will be made of aluminum or lead. It will be made of aluminum or lead.

[00:22:23]Okay, after that, look, you have bedding. Now, look, what bedding is made of? Is it bedding that is soft? The bedding is soft. It would be made of either jute or jute or it would be made of hessian tape or hessian tape or hessian tape or hessian cloth or hessian cloth or hessian tape What is your reply sir, this was a cushion when we increase the length of the tower, will the sag increase or decrease? Jasvir, increasing the length of the tower does not have any effect on the sag.

[00:23:40]Okay, so look here. Will oil-filled cables become its right element? Will it become its right element?

[00:23:48]Oil-filled cables are used up to 30 kV.

[00:23:52]Okay, after that, we have belted cables. Belted cables. Here, I will tell you one. We have belted cables. Note how many belted cables are there? They are used from 11 kV to 22 kV. Then we have screened cables. Which cables are there? Screened cables.

[00:24:14]How many screened cables are there? You will say, sir. They are used from 22 kV to 66 kV.

[00:24:19]Okay, then which one comes to us? Then which one comes to us?

[00:24:23]Pressure cables. Which cable comes to us? Pressure cable, then where is pressure cable used? Sir, it is used above 66 kV. Okay. Then after pressure cable, all- filled cable comes to you. Which cable comes next? Oil-filled cable.

[00:24:39]So where is oil-filled cable used?

[00:24:41]You will say, sir, it is used from 132 kV to 100 kV. Okay. Then after that, gas pressure cable comes to you. Which cable comes next? Gas pressure cable. Gas pressure cable is used above 220 kV.

[00:25:06]Okay. The data has been cleared for everyone. I understand. Everyone, take a note of this data and take a screenshot.

[00:25:13]Quickly, everyone is okay. Next, let's move on. Yes, what is the sheath made of in underground cables?

[00:25:21]We just talked about it, didn't we? Simbas, I, MBAS, quickly, quickly, quickly, the conductor will be made of the conductor. The conductor will be made of either aluminum or copper.

[00:25:35]I have insulation, what will the insulation be made of?

[00:25:38]You will say, sir, insulation, or look, it will be XL PE, or it will be PVC, or it will be rubber, or it will be extra, there will be a lot of extras.

[00:25:47]Okay, then came the metallic sheath.

[00:25:51]What will the metallic sheath be made of? Sir, it will be made of lead, or it will be made of aluminum. Okay, then came the bedding. Now, what will the bedding be made of? I just did it, sir. The bedding will be made of either hessian tape. Okay, it will be hessian cloth, or it will be jute. Okay, after that came the armoring. Now, what will the armoring be made of? The function of armoring is to protect against mechanical force, to protect against mechanical injury, to protect against mechanical damage. So, it will be made of steel tape.

[00:26:23]What will it be made of? Of steel tape. Then came the serving. The serving is the outermost layer, so the serving is also made of either jute or Asian tape.

[00:26:36]Okay, so what did you ask here? They kept talking about the cold, talking about this metallic cold, what is it made of? Or will it be written as lead or aluminum, then sir, what will be made of lead? Yes, it is clear to everyone, let's move on, let's go ahead, let's go, where is the good HVDC technology used? If you have AC, say high voltage AC system, high voltage AC system, okay, then you have HBDC, high voltage DC system, high voltage DC system. Let's talk here, where is the HVDC system used, for short distances and low power, for noise distances, for efficiency, for log distances, for greater efficiency, for log distances, or for greater efficiency, for short distances. Yes, sir, what will be made of this? Are you doing greater efficiency, long distances? Let's do this too. Let's do it okay let's all quickly everyone has to attend this lesson with me on one side we will write see AC and on the other side we will write DC offline did it not Faslaka people are doing it again okay your revision will also be done write AC system on one side write DC system okay if I talk first I will make you write four points which are important from the point of view of the paper okay doing theory is very important now you I will make you write as many points here many of your dots will be cleared here okay see first let's talk then what about skin effect skin effect come then see skin effect happens in AC skin effect does not happen in DC then okay corona corona corona happens more corona happens corona happens in persia what will happen with it okay and if I talk about people then see In AC there will be resistance, in AC there will be reactance and in AC there will be capacitance but in DC there will be only resistance.

[00:29:15]Okay, after that comes voltage regulation.

[00:29:20]Voltage regulation, see, is the voltage regulation bad in AC or can we say that the voltage regulation is high? Let's talk about the latter. In DC, the voltage regulation is good, but the voltage regulation of the DC supply is good, that is, the voltage regulation is low. Okay, then let me talk next, let's talk about transmission. Let's talk about transmission. Transmission in AC is expensive.

[00:29:53]Transmission in AC is expensive for us, and DC, which is DC supply, when we transmit 765V and 500V, and when we send DC supply at 500V, it is 500k, when we transmit DC supply, it is cheap.

[00:30:12]So, its efficiency then became less and then its efficiency then became more. But if I talk about distribution, that is, small supply, okay, small supply, then look, in small supply, in small supply, AC is cheaper for us, in large supply, DC is cheaper and AC is cheaper in small supply, so AC became cheaper in small supply and what happened to DC in small supply, then it became expensive. Okay, so the points are clear to everyone, now look at HVDC, look at HBDC, when we send over long distances, we will send over long distances, we will transmit, then what will be the efficiency we will have, it will be greater, there will be more efficiency, it will be the right answer. Take a screenshot quickly then move on let's see the next cushion yes standard wire standard wires are used specifically so that one has the stand wire war to reduce the skin to reduce the matte fee to eliminate the proxy and both the yes answer quickly what will happen see the right answer is coming very good very good first of all let's understand see see see this is what happens solid conductor you are looking at solid conductor no see there is no gap etc in it one is made of single single material one is made of single material see this is what happens stand conductor small conductors are made of small conductors when we move it will be flexible ok sir then after that the skin effect in them is less in them next we will skin We will also study the effect. In these, the skin effect is less.

[00:32:40]Okay, in these, the proximity effect is also less. I will explain the proximity effect to you further. The proximity effect is also less among these, that is, it is visible. We do not use solid conductors.

[00:32:51]Which conductors should we use? Stand conductors? We call them ACS R conductors. Okay, let's see next. In transmission lines, sag is less affected by what. Okay, sag in transmission lines.

[00:33:11]Out of the following, sag is least affected by what.

[00:33:14]In transmission lines, the one that has its own sag, see sag. Not everyone knows that it has become their own pole and the tower that hangs its own conductor from the pole.

[00:33:22]Okay, there is a gap between the conductors.

[00:33:25]What do we call this? We call sag. So, sag is less affected by what? The length of the span, the weight of the conductor, the weight of the snow, or the color of the conductor.

[00:33:41]Tell me something.

[00:33:42]What is the least affected by sag? What is the right sir of everyone? Why do you see that we are talking about the formula of S?

[00:33:58]Okay, double means weight, so the more the weight of the conductor, the more the sag will be.

[00:34:05]L means span, that is, the distance between the poles. Okay, the distance between the poles. If the distance between the poles is more, then what will happen to you, the sag will also be more. T means tension, strain, tension, strain, if the tension is more, see the conductor tension will be more, then what will happen to the sag? It will be less. The opposite happens, see if both the tensions are more, then what will happen to the sag? It will be less. And there is one, look, conductor or conductor, ice has frozen on it. If ice has frozen on the conductor, then the conductor that comes down will be affected by these three, but the conductor, whether it is blue, yellow, red, has very little effect on the sag. The color of the conductor has very little effect. Therefore, as the safety factor increases, the sag will increase. Jasvir, if the safety factor increases, the sag will decrease. Yes, for the operating line, what is the sag in summer?

[00:35:07]Okay, they keep asking about sag.

[00:35:10]How is the sag in summer? It is less than in winter, more than in winter, the same in winter, or none of these. Look, it is your conductor.

[00:35:23]It is your conductor. Okay, now see, if we talk about summer, then the temperature is high in summer.

[00:35:32]If the temperature is high in summer, then the conductor will become soft.

[00:35:40]Okay, when someone assumes that something like iron or something like aluminum will get hot, it will neither become hot nor will it become brittle. If your conductor becomes soft, it will not If the conductor becomes soft, then the conductor will come down further, which means that the sag will increase further. If the sag increases further, then with the increase in temperature, the sag will increase, that is, in summer, the temperature is high and the sag will also increase, and in winter, the temperature is low and the sag will decrease.

[00:36:13]Okay, so let's see what will happen in the summer.

[00:36:18]What will happen in the summer compared to the winter? Then it will be more. It will be more.

[00:36:21]You will have the right answer. Okay, GB will be the right answer here.

[00:36:28]Yes, what is coming? Increase is coming. Very good. Come on, look at this cushion. It's a very cute cushion. Match the transmission line given in column A with the corresponding voltage in column B.

[00:36:41]Okay, on one side, you have primary transmission, primary distribution, secondary transmission and secondary distribution. On the other side, you have been given four volts. So, tell me how to match all four of them with each other.

[00:36:57]Tell me if it will be the right answer.

[00:36:59]You should also be able to do such statements.

[00:37:04]Yes, everyone, answer this quickly. What will happen?

[00:37:09]Okay, Armaan's answer has come.

[00:37:14]Look, how much is your primary transmission? It is 132 kV, that is, the first one has become A, the primary distribution, how much is the primary distribution? You will say, sir, how much is the primary distribution?

[00:37:30]33 kV, okay, then the second one has become B, the secondary transmission. Sorry, sorry, sorry. Correct this a little. Let's correct it. First, you have this, then see. Transmission, sorry, let's talk about the secondary transmission. The secondary transmission has come. You will have 3 secondary transmissions, not primary distribution. The secondary transmission will be 33 kV, that is, then you have what happened to the first one. What happened to the second one? It has become B, okay, and after that, you have the primary distribution. Okay, the primary distribution will come to you. 11V means that the second one will become C and the secondary distribution will have 400 volts, that is, the fourth one will become D. Oh look, the first one is A, the second one is C, the second one is C, the third one is B, the third one is B, the third one is B, the third one is D, so C is C. You will have the right answer here.

[00:38:51]Yes, it was coming, not everyone's, here you will have the right answer, who answered first, look here, Armaan's answer was wrong, not to rush, but not to rush, it is right.

[00:39:04]Sir Primary Distribution 11 kV Primary Distribution 11th Yes Yes Jasvir Okay So I have the right answer Let's use the data Let's do it Let's move on Let's see Which of the following statements is not true for the effect of AC skin effect In the following statement is not true regarding the skin effect in AC transmission line See Which statement is wrong for the skin effect in AC Which statement is wrong for the skin effect Read the statement asking Come see It says that the skin effect depends on the nature of the conductor So the correct thing is written It says that the skin effect is less in solid conductors and better in standard conductors It says that the skin effect is less in solid conductors than in standard conductors So what is the thing It is written incorrectly. We have just read it. If you have a solid conductor, the skin effect will be more in a solid conductor, and if you have a standard conductor, the skin effect will be less in a standard conductor. Okay, when the diameter of the conductor is less than one centimeter, the skin effect is very small. This is also written correctly. The skin effect is negligible when the supply frequency is below 50 Hz, that is, if your frequency is low, then it is said that the skin effect is also low. This is also written correctly, so here you have the right answer, what will happen to CD and D? Let's understand the skin effect. Look, your conductor is the current flowing above the conductor. Look, the surface of the conductor is the surface of the conductor. Neither the surface of the conductor nor the surface of the conductor is the current flowing above the conductor.

[00:40:54]We call this the skin effect. Look, the current does not flow in the inner part. If the current does not flow in the inner part, then more current flows in the outer part. We call this the skin effect. Look, what does the skin effect depend on? The skin effect depends on conductivity and if your conductivity is high, if your conductivity is high, you will also have more skin effect. Remember, the conductivity is high.

[00:41:20]If you have more permeability, then the skin effect will also be more. If you have more conductivity, then the skin effect will also be more. If you have more resistivity, then the skin effect will also be more.

[00:41:34]If you have more conductivity, then the skin effect will also be more. And if you have more resistivity, then the skin effect will be less. These four points have been cleared up for everyone. If the conductivity is more, then the skin effect is more. If the permeability is more, then the skin effect is more. If the resistivity is more, then the skin effect will be less. It's cleared everyone, let's see what type of national cable is best used for voltages up to 11 kV? Look, this cushion has come in PSTCL AWSA 2026, so you have to tell me what will be the correct answer for it?

[00:42:17]Which cable do we use up to 11 kV?

[00:42:20]I had just told you, which cable do we use up to 11 kV? The answer will be belted cable. I had told you that from 11 kV to 22 kV, we use pressure cable more than 66 kV. Oil field cable is more than 200 kV and gas field cable is more than 30 kV. Oil field cable is more than 32 kV and gas insulator cable is more than 220 kV.

[00:42:56]You have to remember all this. So, sir, what cable will you have? They say that power transmission over transmission is high.

[00:43:17]Corona loss is dashed. In DC, corona loss is dashed. Write corona loss here.

[00:43:25]In DC, corona loss is dashed. It is more than AC, less than AC, infinite or zero. Now we have talked about it. If you are asked about skin effect, They will see the skin effect. The skin effect only happens in AC. There is no skin effect in DC because there is no changing magnetic field in DC. That is why if we talk about corona effect, if we talk about corona effect, then you will have corona effect in AC as well as in DC but it will be more in AC and in DC you will have less here.

[00:44:04]Okay, then what will happen to corona effect in DC then the voltage will decrease. What will happen with AC? It will decrease. Right sir, Haji is coming. Everyone's Jasvir Sandeep is another Sandeep. Okay. Okay. Okay. Everyone's right. Okay What kind of insulation is there? Is it varnish insulation, bitumen insulation, ceramic insulation, or is there no need for any kind of insulation? What will be the element of this, then what will be the right answer of it?

[00:45:11]No insulation. Look at this. Here is what happens inside the AC ACSR conductor. You fill the steel inside.

[00:45:19]Okay, how many conductors do you have inside? One, two, three, four, five, six, seven.

[00:45:24]You have steel conductors. And the rest.

[00:45:27]Look at how many conductors do you have? These are aluminum conductors. We call them ACSR conductors. Okay, look at aluminum core steel reinforced conductors. The formula for these conductors is 3x square math.

[00:45:44]Look at how many stands are one, two, three, and four. The total conductors for four stands will be 37 conductors. Okay, so look here now, what's between the ACS conductor, which is your aluminum, and the one you have, which is steel, there is no insulation between them, no insulation, no insulation, no insulation, no insulation, no insulation.

[00:46:09]Okay, let's see what are the characteristics of ACSR conductors. Let's see. They have good mechanical strength because if they had steel in them, they would have good mechanical strength. Then they have high conductivity. Because aluminum is a good conductor, they would also have high conductivity. They have low resistance, that is, low resistivity.

[00:46:29]This is also written correctly. Talking about low specific resistance, that is, resistivity, this is also written correctly. They have more flexibility. They have more flexibility, that is, they are flexible. And one more point, write that skin effect is also less visible in them. The skin effect is also less visible.

[00:46:50]Okay, you have all the features, take a screenshot of the ACS R conductor, quickly everyone, and move on.

[00:47:00]Let's see which of the following is not a property of insulating material used for cables.

[00:47:06]Okay, which of the following is not a property of an insulating material? Let's assume you want to make an insulator.

[00:47:14]What do you have to do? If you want to make an insulator, then which of these properties should not be present in order to make an insulator? Should there be high dielectric strength?

[00:47:24]Absolutely, it should be. The higher the dielectric strength, the more the insulator will withstand the voltage. So what should the dielectric strength be? It should be high. What should the insulation resistance be? It should be high. But what should the permittivity be? It should be low permittivity? I did it in offline class and also did it online. What should the permittivity be? It should be low permittivity?

[00:47:51]What did they write here? High permittivity is wrong. Okay, yes, very good, very good, very good. It was coming. Not everyone's cushion is good. No, let's have a good cushion. See how long a small transmission line is. What is the length of a small transmission line?

[00:48:08]120 km, 80 km, 400 km or 200 km.

[00:48:15]Look at the three types of transmission lines. I have one. A small transmission line. So, a transmission line. Okay, then I have it. Medium transmission line is okay. Medium transmission line is okay.

[00:48:33]Then you have long transmission line.

[00:48:39]Long transmission line. If you talk about short transmission line, it is less than 80 km. If you talk about medium, it is from 80 km to 199 km. If you talk about long transmission, it is more than 200 km. More than 200 km. Yes, yes. And if you talk about voltage, it is up to 20 kV. It is from 20 kV to 100 kV. It is more than 100 kV. Yes, yes. And if you talk about length into frequency, and its length into frequency is up to 40 Hz. How much is its length into frequency? Yes, it is up to 10 Hz.

[00:49:45]And its length into frequency is more than 10 thousand.

[00:49:53]Okay, please take screenshots of all those who haven't done so yet.

[00:49:58]Sir, medium does not go up to 150, no, no, Jasvir, medium, yours will go up to 199. This is accurate data. Yes, accurate. Yes, accurate data. In many places, you will get 150, 180, 160. But the thing I wrote is a line on a stone. Yes, let's see what will happen to it. Then, in this 80 km, let's see.

[00:50:31]Which of the following does not affect the corona effect?

[00:50:38]Which of the following does not affect the corona effect?

[00:50:40]See the corona effect. I had also posted a video on Instagram. If you have seen it, how many of you have seen it? I had posted a video on Instagram about the corona effect.

[00:50:51]Okay, corona effect.

[00:50:55]So, what things do not affect the corona effect? ​​I am asking you about rain, break, etc., the radius of the driver, the radius of the driver, the power factor or frequency. Let's write it down. See the corona effect. See the corona effect. I will tell you a lot of data in class.

[00:51:20]So you wo n't get them anywhere, they just make cushions and let's give you a summary of the work, but if they will make you with data, then it will be your benefit. Okay, look at the corona effect. Jasvir has seen it. No, the corona effect does not depend on anything. Look at what the corona effect depends on. Look at what the corona effect depends on. One, it depends on the size of the conductor.

[00:51:49]Okay, if the size of the conductor is larger, the area is larger, then the corona will be less. Let's talk about it later.

[00:51:57]If the frequency of the conductor is higher, then the corona will also be higher. Then, if the voltage is higher, then the corona effect will be higher. If the voltage is higher, then the corona effect will be higher. But it does not depend on the power factor. Corona effect does not depend on the power factor.

[00:52:21]Power factor lags leading.

[00:52:24]Okay, unity power factor. That will not affect the corona effect. Corona.

[00:52:30]There are things that affect the effect and the corona effect does not change with the power factor.

[00:52:38]What is permittivity? Yes, tell me the permittivity. Do you have a material? No, this material is okay.

[00:52:47]What does permittivity mean? It is the material that prevents electric field lines from passing through it. It prevents electric lines from passing through it. It prevents electric lines from passing through it. We call it its permittivity.

[00:53:09]Okay. Let's see which of the following effects are associated with transmission lines. Okay.

[00:53:23]Which of the following effects are associated with transmission lines?

[00:53:26]Skin effect, corona effect or proximity effect. All three are related to transmission lines. The same skin effect is also visible in the transmission.

[00:53:36]Corona effect is also seen in transmission and proximity effect is also seen in transmission. So what do you get? Two and three are the effects of the transmission line. Okay, let's see next.

[00:54:02]Which of the following insulators is selected for voltage applications? Which of these insulators will you choose for high voltage applications?

[00:54:16]Which of the following insulators will you choose for high voltage applications? Suspension type Pin type Sickle type Or else or strain type See Jasvir What is the proximity effect?

[00:54:30]You have a conductor. Yes. Yes. And a conductor.

[00:54:38]Current will flow through this conductor. Current will flow through this conductor. A magnetic field will be formed in this conductor. A magnetic field will be formed on this conductor. Yes What will we use? Suspension type. Suspension type insulators are used up to 765 kV. Yes.

[00:55:16]Pin type insulators are used up to 33 kV.

[00:55:20]Cycle type insulators are used up to 11 kV. Stane type insulators are used up to 132 kV or 220 V. Yes.

[00:55:32]Which of the following is a property of the materials used in cables that is divisible? What does divisible mean? It is a desirable property, that is, it is required. Yes.

[00:55:49]Which of these is a property of the materials in cables that we need? It is necessary.

[00:55:54]Desirable property is OK, any cable is OK, insulation in the cable, which insulation is there, no insulation, which of these properties do we need, tell us, what property do you need in the insulation here, should it have low dielectric strength, no, sir, you will say what should be the dielectric strength, should it have high dielectric strength, because it is an insulator, no, what should be the dielectric strength of the insulator, should it be high? It should be non-hydroscopic, that's right. Non-hydroscopic means that it is less susceptible to water. If it is less susceptible to water, then we need an insulator that is less susceptible to water.

[00:56:34]If it absorbs water, then its dielectric strength will be damaged. Okay, then what should be low mechanical strength? It should be high mechanical strength. High mechanical strength is okay. And what should be low resistance?

[00:56:51]High resistance is okay. Clear everyone. Come on, let's see next. Okay, they say that the conductor of transmission power must have the following characteristics. Look at the conductor. When you use a conductor, any conductor you use is okay. Just like we had read ACSR conductor. Neither what properties should a conductor have. I am asking. Which of the following properties should a conductor have? Tell me.

[00:57:21]Which of the following properties should a conductor have?

[00:57:31]Tell me. They say that its specific resistance should be low. I mean, it should be low. It is absolutely correct. Look, if we talk about a conductor, then the resistance in the conductor will be low.

[00:57:42]Neither the resistance of the conductor should be low. It is written right. Guru Ji then says that it should be of low strength and not brittle. Should not be brittle means it should not be old. This is also written correctly. Should not be light or not light. Only then will we know. Should be light.

[00:57:59]Okay, the second line is also written correctly.

[00:58:02]Their cost should also be low and they should also have high tensile strength. This is also written correctly. This means that all these statements are written right here. Okay, so like the class.

[00:58:15]All the children who are watching it, if the class looks good, then watch it next.

[00:58:20]Here is a question asked in PSPCL, it says what should be the minimum clearance for laying power cables near communication lines, then it should be 0.6 meters, note down the data. Let's see what insulators will be used in lines up to 33 kV.

[00:58:43]You want to build a 33 kV line. If you want to build a 33 kV line, then which insulators can you use here? If you want to build a 33 kV line, then which insulators can you use? You can use pin type insulators, you can use real type insulators, you can use POS insulators or you can use stainless insulators. Tell me what insulators can you use in a 33 kV line.

[00:59:19]What will happen? Bye, yes, which insulators can you use?

[00:59:34]Bye, well, look, pin type insulators are used up to 33 kV, that is, you can use them, absolutely you can. Real insulators are used up to 650 volts, we cannot use these.

[00:59:45]Post insulators are used in substations, so you do not use them up to 33 kV.

[00:59:56]Post insulators are used in substations, but they are used for CTPT.

[01:00:00]Yes, they are used for CTPT.

[01:00:02]And the strain insulators can be used up to 132 kV. They can be used up to 33 kV. They can be used up to 33 kV. They can be used up to 132 kV. They can be used up to 220 kV.

[01:00:12]So, one should use the pin type.

[01:00:14]One should use the strain type, that is, the first and fourth. The first and fourth will be the right answer. Yes, there will be a pin, absolutely 100%, and there will also be a strain.

[01:00:38]In an underground cable, the transmission line in an underground cable is compared to the transmission line in an underground cable. The ability to flow current, that is, the ability to flow current, is the ability to There is an underground cable, the current flow capacity is less than the transmission line, more less more medium laser or yes what will be made of reel insulator reel insulator would be like this conductor is inserted in it okay Jasvir yes please tell me the answer to this please tell me the answer to this please what will be made of see a simple thing if we talk about transmission line or overhead conductor which passes above the head then we come to underground underground cable which will be in the ground see which underground cable is not used up to 132V which underground cable is not used up to 132V or sometimes they say 66V but nowadays it is used up to 132V but those conductors which go above the head then we use up to 765KV so that means those conductors which have no current capacity have more Their current capacity is high and the current capacity of the UG cables is less than the current capacity of the cables. So what will be the current capacity of the underground cables? If it is low, then what will be the answer? You will get the right answer. Sir, voltage regulation is very less in underground cables. Let's talk about current here.

[01:02:37]Okay, let's talk about current.

[01:02:40]What type of insulator will you use for 132 kV operation?

[01:02:44]Now, let's check this quickly.

[01:02:47]What insulator will you use for all 132 kV and for 132 kV? Now, let's see the pin type. Sir, we use only up to 33 kV, so we can't do this. Leave it. Okay, we use the shape type, sir, up to 11 kV, we can't do this and we can't do this either, so what will be the answer? Disk, we also call it suspension insulator, what do we call it, we also call it suspension insulator, so what will be the answer? B. Right answer.

[01:03:20]Okay, Fronti effect is such a phenomenon. What kind of phenomenon is it? It is such a phenomenon in which the voltage of the induced end is dashed from the voltage of the rated end, while in a long conduction line, the dashed state prevails. Very very important is the cushion.

[01:03:43]I will not repeat the cushion again.

[01:03:45]You have to do such cushions yourself. Read the cushion carefully.

[01:03:51]Not all of them have much effect on voltage regulation.

[01:03:53]Okay, there is no comparison of their voltage regulation.

[01:04:03]Share it with the class, everyone, yes, see what effect it will have.

[01:04:24]See, there is a front effect, an anti effect, a front effect. Okay, what happens in the front effect?

[01:04:32]Your voltage is called AVS, that is, the sending voltage. Let's assume that you sent 11 kV. Okay, here is your load side.

[01:04:42]Okay, here is your load. Here is the load.

[01:04:44]You sent 11 V, assuming that the voltage you are getting is 13 kV. This is wrong.

[01:04:50]We had sent 11 V, why did we get 13 V? We will let our fans burn out.

[01:04:53]Sorry, our transformer will burn out. So this is what happened. Front effect.

[01:04:58]What happens in the front effect? ​​The voltage you receive is the receiving end voltage. The voltage you receive is the receiving end voltage. The voltage you receive is the sending end voltage. Okay, so the receiving end voltage that we send is the sending end voltage. If it is more than the input voltage, then what do you call it? It is called the Front effect.

[01:05:15]Which effect is called the Front effect? ​​There was a scientist whose name was Front. He discovered the effect. If he did not have it, it would be more than that. When does the effect occur?

[01:05:40]When will the effect occur? When will the effect occur? When will the light be needed? Or when will the light be needed? Then this effect will occur. So what will happen to you?

[01:05:52]What will happen to you? First, look at the front effect.

[01:05:55]What happens in the front effect? ​​The value of the voltage at the induced end is less than the value of the voltage at the received end.

[01:06:05]Look, it is written in reverse here. It is not said that the sending end voltage will be what will happen. Let's see from the receiving end voltage, we said that the receiving end voltage is high, that is, the voltage of the sending end is low and the voltage of the receiving end is high, that is, the voltage of the sending end is low and the voltage of the receiving end is high, and when the transmission line is at what load, when it is at no load, what answer will come, at no load, then it will come up, low will come first, low will come later and then no load will come, that is, the right answer will be. Look, everyone has made a mistake. Look, everyone has made a mistake. The cushion has been rotated. What will happen to the sending and voltage? What will happen to the sending and voltage? What will happen to the receiving and voltage? If it is high, then the sending and voltage will decrease. The first of these will come. You are writing high. You have made a mistake. Read the cushion carefully.

[01:06:55]Read the cushion carefully.

[01:06:59]Okay, let's do this cushion for today.

[01:07:02]We have done so many extra cushions. We have done close to 50 cushions.

[01:07:04]Okay, then I hope you liked the cushions.

[01:07:06]Your revision must have been good.

[01:07:08]After this, those who have got admission in ITI can also get admission.

[01:07:15]And after that, those who have failed, you can also join the new batch.

[01:07:20]Your batch is going offline. Okay, come once and check the content.

[01:07:25]Whichever academy you are studying, come once and do a comparison because there are many in the market. Most academies have many options for you, okay, when there are many options, then you should try it, okay, then those who are officiating should also come, and those who have to get IT admission should also come, and the rest should also get ready for the next one, everyone is okay, now it's time to study, if the posts come, then go to the next one, everyone will meet there, everyone is okay, come to the next one, let's meet again, in the next class, everyone, you will get the PDF, go to Telegram, and the PDF was received, everyone,