KCET2023 | No Solving Only Shortcuts | Current Electricity | KCET Physics 2023

first of Allah we are very sorry so in the candles and so the reason it's simple simplified if you want to help us and all these things so preparing PPT so that next year continuously we should do the videos so foreign foreign so it's very simple we want to focus more on KCET give very good content give very good content actually so either a YouTube channel alone I hope you understand but uh uh very soon very soon and continuously we're stopping all the offline everything we understood the mistakes and now everything where to put it back on video channel everything whatever you want we're going to put it back and thank you so much for people who are taking the course and it's going to help next North Korea and I think we want to start on the digital board so so continuously we stopped everything offline and all so online and give the best content okay so I hope you understood and uh so it's not a time where you know you learn the methods and all you learn the new formulas and lot of things you should know how to handle shortcuts immediately the CE tell it's all about timing 70 minutes 60 Questions so almost literally one question one minute so one middle is all models I'm teaching you the techniques here today techniques CDL you can really do questions really well that is very very very important very first question is an atom electron revolves around the nucleus along a path radius uh they're given how many revolutions per second case the equivalent current is given by the current is known current Formula current and Reno current is nothing but of course I is equal to e by time period R is if you know the formula it's just one second because there's so many formulas we can't remember so many formulas right basic concepts is equal to I is equal to a step it's revolving so it is making how many revolutions these many Revolutions in one second electrons how much charge in one second is foreign four zero nine ten fifteen one five zero from the multiple of fifteen agrico to 1.5 is the answer so here is the calculation basic formula basic understanding questions because one by time period is equal to frequency I have taken all tough questions only easy others are easy you can answer in 10 seconds the voltage across the bulb is 220. so bulb voltage 220 there and 100 watt is there it drops by and then when the bulb for 220 voltage you just tell think whether you know this question or not so if a side of a cube is increased by three percentage what is the change in the volume the radius of a r can say like this during a radius of a circle is measured with the error of 0.03 what is the error in the measuring the area questions have seen that it's very easy is given by X Cube so in the measurement of side of a side of the queue there is a three percent error what is error in the volume they can ask any question like this there's so many questions it keeps coming in very simple so the change in the volume DV is equal to DV by DX into Delta X then period foreign [Applause] V is equal to I can put I is foreign so power is equal to V Square by r this is my mathematics math so now Y and X is actually see the error in the x is 2.5 percentage what is the error in the Y so DX differentiate x square differential into two x so the error is basically now so DV is equal to DV by d x 2 Delta X is simple formula approximately you can do it and this other method also you can do it but it will be some lengthy methods will be there okay so this is more easier 2.5 input only know the formula yeah you think now yourself how much time it will take to solve this if you know the formula it just takes around 10 seconds V Square by r v Square differentiation 2 is going to come 2 times of 2.5 any other formulas so three times four times Mantra so next a wire of certain matte material is stretched by a 10 percentage the node is 20 20 equation again either its new resistance and a specific resistance not just simple what specific resistance resistivity resistivity or no though it does not depend on the area length on all those things it doesn't depend cross-sectionality because resistivity is nothing but resistance per unit length we are rested in the dimensions really so formula in Italy R is equal to rho into building formula into L by foreign right now the resistance of a platinum virus uh they are given a formula the resistance of the Platinum value is zero degree at ohm and 6.8 10 degree celsius the temperature coefficient is equal to R naught into one plus Alpha into Delta formula there so easily they are given everything you can get the answer but see is these two exams I'm not talking about Je Mains in advance of course J minerals are easy only Advanced GE advances it's more about timings more about timing the personal practice more will answer it very fast questions are very simple you just have substance get the answer but I will without solving I'll tell you how much resistance is going to vary and then it's very simple resistance divided by like it's basically a resistance divided by 80 degree celsius and the resistance is to it's in the order of 2 ohm 6.8 ohms something like six point eight or seven oh something like that so then 6.8 resistance per unit degree celsius and divide by 80 degree don't you think the power will be either I think 68 by 800 hours so it's like 68 divided by eight into ten power minus two one don't you think the answer should be in the multiple of 10 power minus 2 in the order of 10 power minus 2 because 68 by 8 68 by eight I'll obviously get some answers so but it is you know resistance per like degree Celsius is what for this this one minus two powers sorry and I'll take some questions that can also show you so we just have to do very fast like this okay so needles is very easy difficult but it's very easy next up a potentiometer has a uniform wire of length 5 meters a bat again potentiometer meter Bridge so potentiometer is uniform I have length 5 meter a battery of EMF 10 volt and negligible inter resistance is connected to between its ends okay a secondary cell candidate is a circuit balance in the length of two or balancing at 200 centimeters that means two meters and the EMF of the second reason is very simple potentiometer you can very very simple Muffler so basically length one to five meter very simple five meter length potential that 10 volts they get distributed across the resistance wire so when you give the 10 volts the 10 volts will get distributed across the wire the resistance via net pedia experience across five five meters and four volts foreign what is this diagram so whatever is EMF the meaning is 10 volts will get distributed across this across this wire across the resistance fire so in a five meter length so pretty voltage drop per unit length Okay so when I connect like this obviously as per see if this is like I don't know this EMF but um that means what the entire voltage should be balanced if it is whatever the EMF what is the voltage drop here in this case so 2 meter again so two uh for ten by five to four volts you do four volts so that when I apply kvl it should become zero 0. in an inputable is very very important for example what is the voltage drop in other part of this that will be how much remaining volt and then you know total 10 volts to either two meters are either remaining three meters so it is is to three questions Okay so velocity is nothing but length of the conductor divided by time area is to Phi n is to 1.6 charge link this to length one meter voltages to current is two foreign foreign now simple questions three ohm is stretched twice its original line when is foreign stretched you can convert like that again sometimes they can ask in terms of density in terms of volume you can convert same formulas in various ways rho is equal to if you want in terms of volume uh suppose if you take the uh area so area is equal to what formula is area volume is equal to area into l so basically now anywhere else twice if you remember this formula row into L Square by uh volume since when you're stretching it volume is not changed limit is only changing from the L square is going to get in terms of density also anything but this answer is very simple it is 12 volts okay let's go first question now a cylindrical conductor of diameter 0.1 me 0.1 mm carries a current of 99 degrees that's really 90 uh milliampere and then what is current it's very simple question current density what is the currency J is equal to yeah and intensity you know J is equal to Sigma current density and a current divided by the area that is the J actually basically current very simple again just numbers today because indicator power 6 is 2.4 that because powers are all different and this is different only six different two point four three one point voltage they only take numbers so J is equal to current current is the 90. area is radiuses or if you remember the formula pi d square by four or you can say half of this that means one by two one by two so three three cancel out there four three is at 12 times 1.2 into 10 power 7. okay in the given arrangement of experiment the meter bridge if aad corresponds to null deflection of gallery Matrix what would be its value if radius of radius of the wire a b is doubled questions in fact I think there's a question 2022 also okay you know the potential potentiometer works in the principle of meat average so resistance you know all these things like R1 by R2 what is the thing is it is same because resistance per unit is a property of the material resistance per unit length it depends on the medial property so if I say mirror so cancel of the five five so it's like basically L one by L again question is since it's not depending on that balancing point will not change as long as the resistance of this store not changing in Bitcoin e resistance so resistance will change or if you replace with something in other material residence permittent will change but it does not depend no R1 battery is L1 by L2 right so what what's answerable what what value if the radius of a b is doubled if the radius double other the balancing points as long as these two are not changing foreign a metal conductor is connected to a left gap of the meter ready left we are connecting what uh meter uh connected to a left gap of the bridge and it is heated and you heat it resistance will increase when distance increases balancing see now we have two gaps Alpha meter Bridge foreign foreign I need uh I am trying to do 10 by 2 5 uh 10 by 2 is 5 and then I'm going to I just want to give a random number for this 50 by okay let's make 50 by yeah 10 okay so we got 20 by 2 and now chain one actually I have to increase this also 50 now I have to make it to 100 and so that uh this also becomes again resistances giving so we need a formula which has voltage and the resistance the voltage is constant so p is equal to what V Square by r so I think if you remember in the previous question R was constant and the V was changing same voltage because they connected in parallel so voltage is same so since voltage is same so power is inversely proportional to the resistance it's very simple so foreign reciprocal because there is no Square alpha or if you want some formula give formula also P1 by P2 will be equal to reciprocal R2 by R1 basically 20 by 10 so and similar 2 is to one directly foreign your two variables two equations you have to convert the quantity equation or you can do like elimination method to get the answer so it's very lengthy now think that but this is very easy answers shortcuts understand the art of elimination we all day the powers numbers okay let me know comment section or I'll keep doing next chapter and so so next video YouTube channel of course this is going to the last video in this YouTube channel for the kcat you can download the sorry you can you know I was also thinking why it is happening all these things like we should do continuously and talk so anyway uh thank you so much for supporting and uh bye bye take care

Channel: SimplifiedMinds Karnataka

Views: 137,194

Keywords: kcet physics, kcet current electricity

Id: saKI9vAKSaw

Length: 41min 51sec (2511 seconds)

Published: Mon May 15 2023