Transient Analysis: Solved Examples on First order RC and RL Circuits

[@ALLABOUTELECTRONICS]

The solution of the examples given for the practice has been uploaded in the PDF format. drive.google.com/file/d/0B3FOmN0FcD6OWFc2OXAtcUtmcXc/view?usp=sharing&resourcekey=0-yNuVb1wrtYbtPSk9wSTHuA

[@jahnavidhanireddy5069]

ALL ABOUT ELECTRONICS

[@bestfriends7607]

Sir plz send me more examples. Very important sir

[@jatinmaheriya2343]

🙂😇

[@sangeethatatineni6214]

How could I ever thank you for saving my life with these short and informative videos

[@brandonKA4993]

wow!!! while going over this in class and reading the textbook, this topic was clear as mud. I watched this and saw how you explained these circuit analysis and I have a greater clarity on what is going on. Keep up the great work on your videos because they help a lot.

[@noweare1]

Excellent work again. I did confirm example 3 using LTspice. The equation is spot on and corresponded with the graph of the current through the resistor at different times.

[@thatguymax]

thank you for these clear videos. they have helped me in my circuits class so much!

[@shashankcholleti2003]

16:22 sir il at 0- and 0+ are equal to 0.75 then y have u writtten at 0 0.375 flows it flows through the parallel resistors isn't sir

[@VanshikaAggarwal-uw4yn]

I think so too

[@dennis.B]

at 5:40, i didn't quite get how capacitor get shorted in the equation. Can you elaborate it more?

[@ganeshmeesala133]

Coz current choose low resistive path to flow, it doesn't flow through 20k ohm resistor and since current is zero, we are assuming there is no 20k ohm there

[@sujatasapte5959]

In last example we have not to find current through inductor.We have to find current through 10 ohm resistor.. So why we used the Inductor Current formula I(L)at t.

[@ALLABOUTELECTRONICS]

That formula is also vaild for finding the current through the resistor. Because we are taking the current through the resistor at t=0 and t = ∞in that equation. Alternatively, if you are still in doubt, you can find the current through the inductor using the same formula and then applying at the KCL at the common node, you can find the current through 10 ohm resistor. 1.5A = IL(t) +2*Ir(t) You will get the same result. I hope it will clear your doubt.

[@sujatasapte5959]

@@ALLABOUTELECTRONICS sir will you make video on that pls

[@ALLABOUTELECTRONICS]

@@sujatasapte5959 I have already covered many similar type of examples on the second channel. Please go through it.

[@amansajwan6411]

Sir we have to find i(t) which is the circuit response or current through inductor so why we are using 0.375 instead 0.75

[@Jinkazamakhan]

We use .75 amp at t=0+ not .375

[@rakhatthenut3815]

We are asked to find the current of one of the resistors, not of the inductor. be careful

[@trupti8440]

Yes we have to use i0+=0.75 in this formula that is current through inductor.

[@waraysplayground26]

Hello, with the 1st problem, initial current is 0.5mA, why you just use 0.5 in the i(t) equation you forgot *10^-3.

[@jeffreyaigbovbiosa7880]

Noticed the same too it could be an oversight

[@prakashkannan2900]

@@jeffreyaigbovbiosa7880Yeah me too noticed the same.

[@prakashkannan2900]

yeah, I too found the same thing, it is 0.5 milliampere, so have to multiply the same with the output!

[@ryandrums2112]

Bruh amazing videos, so clear

[@farhanchowdhury6238]

I don't understand how(in 6:05) the capacitor becomes short circuit(which is fine) but then how did the 20K ohm become short? Can you explain?

[@ALLABOUTELECTRONICS]

20 kΩ resistor is in parallel to the capacitor. When the capacitor acts as a short circuit then 20 kΩ resistor will be in parallel to a short circit. So, it will also get short circuited. I hope it will clear your doubt.

[@sonujss]

you said at t=0+ inductor act as open ckt where it used ????

[@blessoneasovarghese9834]

at t=0+ inductor acts as open circuit only if current through it was zero earlier. If there was already some current flowing through inductor, it will maintain a same current initially.

[@dishuu2714]

10:49 Example 2 why the 2.5A current didn't divide between inductor and resistance branches?

[@ALLABOUTELECTRONICS]

At t= 0-, the entire 2.5 A current is flowing through inductor as it will act as a short circuit. At t= 0+, when the switch is opened, the inductor acts as a current source of 2.5 A and it supplies current to the resistor which is connected in parallel to it. While the current of 2.5 A (form independent current source on the left) will flow through another 20 ohm resistor at t= 0+. I hope, it will clear your doubt.

[@abhijithmadhusoodanannair9830]

NOTHING BUT.........................................................AWESOME

[@mdamanansari7234]

Great job man ... you did an amazing things👌

[@rabecamohammed9518]

@5:47 why does the 20kohm get shortcircuited along with the capacitor?

[@ALLABOUTELECTRONICS]

At t=0+, the capacitor will act as a short circuit. Since, the 20k resistor is in parallel with capacitor, so it will also get short circuited. I hope, it will clear your doubt.

[@rabecamohammed9518]

@@ALLABOUTELECTRONICS Thank you for the explanation! But is it a general rule? As in if something is shorted in a branch, everything in the branch opposite to the first branch will also be shorted?

[@ALLABOUTELECTRONICS]

Yes, in parallel, if any branch is short circuited, then every branch in parallel to it will also get short circuited.

[@rabecamohammed9518]

@@ALLABOUTELECTRONICS Thank you so much!

[@shashankcholleti2003]

5:52 sir the capcitor is shortckted due to its property but why is the 20kohm shrtckted sir why cannot the loop b closed so that it forms a new circuit with 2 20kohm resistors

[@MAAslam-bh8ss]

Sir please give some clarity to the doubts asked by others.... It might help others for getting more clarity information...

[@srilathasunkara150]

Superb and simple explanation 👌

[@luvchugh616]

In question 3 it is given that switch is opened for a long time then it is closed at t=0 so as switch is open and due to rule ki instant change oppose kerta hai then how current is being flow and and at t=0- how inductor act as short circuit????

[@luvchugh616]

Switch to open tha to 0- pe inducors short kaise hoga???

[@luvchugh616]

Pls reply

[@mohammadsyahmibinshebli8239]

on minute 11:50 how he can get 1.5/2..can you explain about how u can get 2?

[@ALLABOUTELECTRONICS]

At t= 0-, the switch is still open. The inductor will act as a short circuit and therefore, only two 10 ohm resistors are there in the circuit. So, current will get equally get divided between two resistors at t= 0-. I hope it will clear your doubt.

[@gold7091]

in 3rd question while finding time constant why do we take Req at t = 0+ and not at t = infinte? why should inductor be included?

[@kamalkishoremahato2673]

Sir please can u explain me why u put Ic(infinity)=0??? At time*8:22*

[@ALLABOUTELECTRONICS]

If you look at the circuit at t= infinity at 7:18, then at t= infinity, the capacitor will act as open circuit and hence no current if flowing through capacitor. Therefore, Ic (infinity) = 0. I hope, it will clear your doubt.

[@kamalkishoremahato2673]

@@ALLABOUTELECTRONICS clear sir , thank u

[@singiri697]

Sir at 5:50 why is 20k ohms resistor is short?

[@raz7543]

Because potential is same in parallel .zeo potential simply represent by wire.

[@AssirThota]

Isn't the inductor going to be open circuit at 9:50

[@ALLABOUTELECTRONICS]

The circuit which is shown at 9:50 is for t=0-, where the switch is not opened yet. That means the circuit is in steady state condition. And therefore, inductor will act as a short circuit. I hope, it will clear your doubt.

[@mydogromishort2902]

In 2nd example why current you get in negative value (-2.5A) passing through inductor? 🤔

[@ALLABOUTELECTRONICS]

It is not negative. It is +2.5 A only. There is no negative sign.

[@harshadgupta4384]

in which particular branch we have to find out i(0-) and i(infinite)

[@ajaychopra9509]

which tablet/phone do uu use ?

[@pratiklodha5108]

At 11:54 from where has that 2 in denominator come from

[@ALLABOUTELECTRONICS]

At t=0-, before the switch is getting closed, the 1.5A current is getting divided between the two 10 ohm resistors. (Considering inductor as short circuit). That's why current through inductor at t=0- would be 1.5/2 = 0.75 A. I hope it will clear your doubt.

[@pratiklodha5108]

@@ALLABOUTELECTRONICS thank you for clearing my doubt

[@maheshkalluri502]

Bro..but as two 10ohm resistors are in parallel Req=5ohms

[@briankibet9387]

sir please do video of two port network

[@thirumal1086]

Very good explanation..please do more videos on second order series & sinusoidal ,step ,square response as well as the parallel rlc ckts , concept s damping factor ,root locus

[@rutendogwese5201]

12:07 where is the 2 coming from

[@SovereignSonu]

Because of symmetry ( same 10 ohm resistor)

[@vineetyadav-m1c]

6:48 WHY CAPACITOR ACT AS OPEN CIRCUIT???

[@madhusmitabehera500]

Sir excellent explanation ....Thank u....

[@aryankumar87771]

Sir in example 2 at t (0+ ) why is the entire current assumed to be going towards the 20 ohm resistor in parallel with the inductor ? Why can't a part of the current go towards the other 20 ohm resistor ?

[@ALLABOUTELECTRONICS]

If you observe, at t= 0+, there are two closed loops. Each with 2.5A current source with 20-ohm resistor. So, at t=0+, the current flowing through each 20-ohm resistor will be 2.5A. But in the example, as we have been asked to find the voltage across the bottom 20-ohm resistor, I didn't mention about the second resistor. I hope it will clear your doubt.

[@alienmoondudes8071]

What if the risistors aren't the same resistance. Will they be -V/R?

[@vaikh8450]

@@ALLABOUTELECTRONICS sir please be more specific . Unable to understand

[@SaurabhKumar-gc1ko]

@@ALLABOUTELECTRONICS how is it possible why won the 2.5 A current pass through short circuit instead of going through resistance?

[@satyamev_jayatey_]

@@ALLABOUTELECTRONICS why there is current in bottom 20 ohm resistance if should not, all current is through short circuit... Then voltage across bottom 20 ohm resistance should be 0 sir

[@beryyyllium]

hello, sir. in example 2, why is the voltage at the resistor negative?

[@siddharthareddy3071]

The current and Voltage are in opp. direction

[@陳致廷-c1n]

amazing explanation!!!

[@rishabhtiwari3545]

sir please give the answer of pdf question for confirmation...only answer

[@VAISHNADEVIGECEUG-]

sir its not opening in google drive sir

[@ALLABOUTELECTRONICS]

Ok, I will check. But it was working till now. Anyway, I will check it once again and if required, will update the link.

[@ALLABOUTELECTRONICS]

Please try now once again. And still if you face any difficulty, let me know.

[@mayankprajapati9719]

Hi there was a superb video and it is easy to learn. My humble request is plz make video about intial condition this is chapter of Circuits and network. (BE EC 3rd Sem)

[@ALLABOUTELECTRONICS]

I have already made a video about the initial conditions. Please check the following video: kzbin.info/www/bejne/aYrMn6CYoLpjeqc

[@yuktatayi4801]

In the third example at t =infinity, why is the inductor considered as short circuit and not as a current source along with the short circuit?

[@ALLABOUTELECTRONICS]

At t= infinity, the circuit is in steady state. so inductor will act as a short circuit. And the current which was flowing through the inductor will continue to flow through it. So, here there is no need to show it through a separate current source.

[@amaljithodukkathil8247]

why I(0+) is taken as the current flowing through the switch but not through the inductor?

[@ALLABOUTELECTRONICS]

Hi, would you please mention the timestamp where you are refering. It would easy for me to answer your question.

[@Noname-nw9gt]

​@@ALLABOUTELECTRONICSat 13:00

[@galaxyfarhan]

please help me. my lecture give me quiz but there is no R. how can i find that resistor :(

[@mayurshah9131]

Superb Presentation!!

[@venkatalokesh1117]

Sir in extra example 1 At t=0+ why 8ohm resistor is considered?..

[@varunborugadda]

sir at 12.54 why did you take the 0.75A of current as leaving for the node ..why it can't be incoming?? please answer my question

[@ALLABOUTELECTRONICS]

If you apply KCL at that node, then remaining 0.75 A current should leave the node towards two 10 ohm resistors. Similarly, at the datum node or reference node, the summation of currents through resistors and 0.75A should sum up to 1.5 A. And that is only possible when current is leaving through resistors and not entering into them. I hope it will clear your doubt. And still, if you have any questions then do let me know here.

[@varunborugadda]

ALL ABOUT ELECTRONICS Thank you sir..I got my doubt clarified..

[@insaneeeeeeeeeeeeeeeee]

At 5:50 why resistor is short circuited

[@ALLABOUTELECTRONICS]

Resistor is in parallel to capacitor. Since, capacitor acts as a short circuit, the resistor will also get short circuited. I hope it will clear your doubt.

[@fazilahmadpala5472]

Sir why you short circuit the resistor at 5:50

[@fazilahmadpala5472]

Also at 9:53 when u short circuit the inductor u also short the resistor which is in parallel with this inductor.can u explain sir

[@ALLABOUTELECTRONICS]

At time t= 0+, the capacitor will act as a short circuit. And the resistor is in parallel with this capacitor. Ao, it will also act as a short circuit.

[@ankitchaudhary2074]

sir, can we use this formula 【i(t)=i(inifinite) + ( i(0)-i(infinite))*e^(-t/T)】for resistor also???

[@lakshjaisinghani7813]

The V/I relationship for resistors is constant, we use Ohms law to determine them. The value of voltage and current also change instantaneously, so there is no need for i(infinite) and i(0).

[@VAISHNADEVIGECEUG-]

SIR BUT FOR SOLUTION IT IS NOT OPENING SIR IT IS SHOWING THAT GOOGLE DRIVE-ACCESS DENIED SIR

[@ALLABOUTELECTRONICS]

I will check and update that link. I think the old links are not working anymore. Will update them.

[@VAISHNADEVIGECEUG-]

@@ALLABOUTELECTRONICSOK SIR

[@shankysays]

in qs 3 , why you used i 0+ as .375 ? should it be .75 ?

[@ALLABOUTELECTRONICS]

I(0+) current through the resistor will be, 0.375 A, as 0.75 A current will be divided between two 10 ohm resistors. If you are taking about inductor current at t=0+, it is 0.75 A.

[@ShawnDypxz]

@@ALLABOUTELECTRONICS So, that's why we should use 0.75 as initial current in inductor

[@agileducation]

@@ALLABOUTELECTRONICS Shouldnt I use the current in the Inductor (0.75) not the resistor (0.375)? Plus I don't understand how the current in the resistor was 0.375 .. we completely ignored the main current source in this computation

[@subhabhaskaran1827]

At 10.47 why it is minus 2.5A ???

[@ALLABOUTELECTRONICS]

Because the Vx is measured from the right to the left. I mean positive terminal is on the right side, while the negative terminal is on the left side. While the current is flowing in the anti-clockwise direction (from left to the right in resistor). that's why there is a minus sign. I hope it will clear your doubt.

[@subhabhaskaran1827]

ALL ABOUT ELECTRONICS Thank u

[@pavansaigrandhi7284]

For finding equivalent resistance we have to short circuit the independent sources or open circuit them??

[@ALLABOUTELECTRONICS]

If the independent source is voltage source then it will be short circuited. If it is independent current source then it will be open circuited.

[@hafeezorakzai3589]

Sir why you divide current 1.5 by 2

[@anantapadmanabhmyatagiri]

Its because when two branches of same resistances are present then current gets equally distributed among those two branches. U can also use current division rule to verify it.

[@its_yantiw_15]

At 8:51 E to the power 25t kaise hua...?

[@imSurajsingh24]

1÷40×1,000 = 25 as it is given that 1÷40 and unit is given in ms, so it is 25

[@bhaskaralakshmiganisetti3779]

At 11.53 why inductor shortckt At t= 0- the switch is opened that means no current flow in that case inductor is oc Plz clarify my doubt

[@ALLABOUTELECTRONICS]

Although the switch is open at t=0-, the current will still flow through inductor via a 10-ohm resistor. If you closely look the circuit, the 1.5A current will through 10-ohm resistor and, 10hm resistor and inductor pair. I hope it will clear your doubt.

[@bhaskaralakshmiganisetti3779]

@@ALLABOUTELECTRONICS tq sir

[@babanpreetsingh9800]

thank you so much sir for making such a usefull vedio

[@aarjuparween8724]

In 1st question, we can also find capacitor voltage first at t>0 and then we can find ic(t) across capacitor then why answer is differing. Please explain

[@venkatalokesh1117]

We cannot find capacitor voltage at t>0.because.there it is open circuit.

[@keertilata20]

Thankyou sir, you cleared all my doubts!🙏

[@SaurabhKumar-gc1ko]

in 2nd question voltage across 20 ohm should be Ldi/dt but since at t=0+ di/dt is 0 voltage across 20 ohm should also be zero ? please clarify it If mine explantion is wrong explain it how?

[@ALLABOUTELECTRONICS]

You also need to consider the initial condition. At t= 0-, the current is already following through the inductor. You also need to take this into consideration. What you are saying is true, if no current is flowing through the inductor at t = 0 -.

[@kolluruyashwanth9381]

In parallel rlc circuit how can we consider case 4: R=0 as R is in denominator of alpha But you explanation is awesome

[@ALLABOUTELECTRONICS]

Yes, That's by mistake. It should have been R = ∞.

[@apalabukun5076]

How do i know when i am to find the current at infinity ?

[@003_maliksheeza3]

SIR in qno 3 ,the question was like the circuit has been open for a long time and that at t=0 the switch is closed. that means at t=(0-) inductor should have been an open circuit becoz the current flowing is zero n in t=0+ also inductor should act as open circuit.why u have shown it as closed circuit as the circuit has closed just then ?

[@ALLABOUTELECTRONICS]

The property of inductor is that it opposes the instantaneous change of current. It means that if any current is flowing through inductor at t=0-, then same current will flow at t=0+ too. Here in example 3, at t=0-, the current through the inductor is 0.75A. So, the same current will continue to flow through inductor at t=0+ as well. I hope it will clear your dobut.

[@003_maliksheeza3]

thnks alot..

[@CorporateCat]

In example 3, if current through inductor at t =0+ is 0.75A as you said then why have you taken i(0) as 0.375A at 16:18 in the final formula?

[@ALLABOUTELECTRONICS]

Here I(o) is the current through 10-ohm resistor which is in parallel. I think you misunderstood the resistor which is in series with an inductor. Please check it once again. And still, if you have any confusion then do let me know here.

[@bhaskaralakshmiganisetti3779]

@@ALLABOUTELECTRONICS sir at 11.53 but in the question u don't mention its charged for some time how to take it as a short ckt ( can I take it as charging from initial(0A))

[@iamtomcstllo]

Sir, how about if the current source is being series with RC circuit? what is the proper computation for that? thanks

[@ALLABOUTELECTRONICS]

In that case, the current through the circuit will remain the same. Only the voltage across the capacitor will change with time (as capacitor charges)

[@Sudheer-q2z]

Hlo bro given circuit is with source or without source how can we gues????

[@ALLABOUTELECTRONICS]

If the circuit has any voltage or current source then it means that, some source is connected with the circuit.

[@siddharthareddy3071]

Eg. 2 At t=0, shouldn't the Inductor become Open Circuit?

[@ALLABOUTELECTRONICS]

I am referring to the steady state condition before the switch was opened. In steady state condition, it will act as a short circuit. I hope, it will clear your doubt.

[@siddharthareddy3071]

@@ALLABOUTELECTRONICS Yes, it did. Thank you.

[@chandrasekar3653]

Sir to find I(t) why are we considering the current through a resistance parellel to the inductor in example 3

[@ALLABOUTELECTRONICS]

Because the current I(t) is the current flowing through the 10-ohm resistor. And to find that we need to consider these resistors. I hope it will clear your doubt. If you still have any doubt then do let me know here.

[@chandrasekar3653]

Sir in the first problem how can u write the current equation I(t) for the capacitor as it is mentioned already that is used for inductor

[@ALLABOUTELECTRONICS]

Are you talking about the first problem solved in the video or the practice problem given in the description?

[@language_loom]

If capacitor is shot circuited then why the parallel register also gets short circuited ??? Please help 🙏🙏🙏 🙏🙏🙏

[@ALLABOUTELECTRONICS]

When the capacitor acts as a short circuit then it offers zero resistance. And anything which is in parallel to it will also get short-circuited (Req = R1*R2 / (R1+R2), if R1 or R2 is zero, then the equivalent resistance Req = 0). Because the entire current flows through the capacitor. I hope it will clear your doubt.

[@venkatalokesh1117]

sir.in example 3. At i=0- I(l)=1.5/2..from where did we get 2. Can you say?

[@ALLABOUTELECTRONICS]

1.5 A current is getting divided between the two 10 ohm resistors. That means half of 1.5 A (0.75A) will flow through one 10 ohm resistor and the remaining 0.75 A will flow through second 10 ohm resistor. That's why its 1.5/2. I hope it will clear your doubt.

[@venkatalokesh1117]

@@ALLABOUTELECTRONICS ss very clear

[@g.nagarajug.nagaraju8656]

@@ALLABOUTELECTRONICS at t=0- as inductor is short circuited then three 10 ohm resistors will be there.then current is 1.5/3.but why 1.5/2 I did not understood please explain

[@bharathin8180]

how to check transients and solve the problem

[@vangelion6116]

time (0) in inductor should be open circuit time (infinity) short circuit misleading info.

[@RishabhKumar0094]

sir in example 1 how you used formulla of inductor current as capacitor current

[@ALLABOUTELECTRONICS]

It is not inductor current. Its capacitor current only. The formula I (t) = i (∞) + [ i (0) - Ic (∞)] * e^(-t/T) is the general formula for first-order RC or RL circuits. It can be used for both inductors and capacitors. Only the time constant T will change. For RC circuit T = RC. For RL circuit T = L / R. I hope, it will clear your doubt.

[@VAISHNADEVIGECEUG-]

SIR NOW ITS WORKINKG SIR THANK YOU SIR

[@jayarangarakesh4581]

for i(0) ,should we take i(0+) or i(0-) ?

[@ALLABOUTELECTRONICS]

I (0+)

[@mayankprajapati9719]

There was one doubt if value of the is given then how to find e^( )..

[@SomnathMalik__EC]

Waha t>=0+ bola tha t>=0 nhi. Donome difference nhi hota kya?

[@zebrhehagos6233]

It is a great explanation but , in the third example how can the inductor acts as a short circuit at t=0?

[@zebrhehagos6233]

I mean at t=0_,,how it acts as short ckt? wasn't it open long before t=0?

[@ALLABOUTELECTRONICS]

If you observe, the switch is connected to the resistor (and not to inductor). So before t=0, in steady state condition, it will act as a short circuit. (i,e at t=0-). And when the switch is closed, it will act as a current source. I hope it will clear your doubt. If you still have any doubt then do let me know here.

[@zebrhehagos6233]

Exactly, I have gotten it.

[@sakthivishvanathan9820]

Sir u r telling that two resistance which r parallel are in series with third resistance,then how can u divde voltage equally between 3 resistance (example 3) pls explain me🙏🙏🙏

[@ALLABOUTELECTRONICS]

Before time t=0, when the switch is open, in steady-state, the inductor will act as an open circuit. And hence, 1.5A will get divided between two 10 ohm resistors. (i.e 0.75A)(Another 10-ohm resistor is still open at t=0-). At time t=0+, once the switch is closed, then there will be three 10 ohm resistors in the circuit. But as you are aware, the inductor opposes the instantaneous change in the current. That means current through the inductor at t=0+ will also be 0.75 A. Hence, the current, through a resistor which is in series with inductor will also be 0.75A. The remaining, 1.5 - 0.75 A will get divided between the two resistors. Now, at a steady state, once again, the inductor will act as a short circuit (after t=0+). And in that case, as shown at 13:59, three resistors will be in parallel. So, current will get equally get divided between them. I hope it will clear your doubt.

[@sakthivishvanathan9820]

@@ALLABOUTELECTRONICS thank you sir 🙏🙏🙏

[@nayeemchadinoo8092]

in the example 3, i0+ is .75A but in the formula we have write i0+ is .375A plz tell me

[@ALLABOUTELECTRONICS]

See, the initial current through the inductor is 0.75A. But we have been asked to find the current through the 10-ohm resistor. (The second 10 ohm resistor which is in parallel with another 10 ohm resistor) So, at t=0+, out of 1.5 A, 0.75 A current will flow through the inductor. And remaining 0.75 A current will equally get divided between two 10 ohm resistors. That's why it is 0.375A. I hope it will clear your doubt.

[@sarangghatkar3937]

Sir can you please provide the solved examples with all minor details in the form of pdf that you have solved for practice & please refer textbook for us.... Our exams are round the corner please help sir

[@ALLABOUTELECTRONICS]

Yes, I will upload the pdf of solved examples in 2-3 days. And you can refer books like Network analysis by Van Valkenburg (But initially it will be slightly difficult to understand) Or you can refer Network analysis and synthesis by S.P Ghosh and A K Chakraborty

[@ALLABOUTELECTRONICS]

The solution of the examples given for the practice has been uploaded in the PDF format. drive.google.com/open?id=0B3FOmN0FcD6OWFc2OXAtcUtmcXc

[@sarangghatkar3937]

Thank you sir

[@taruntej7867]

At 10:14 how iL(0^-) = 2.5 A

[@ALLABOUTELECTRONICS]

At t=0-, the switch is in a closed condition, and inductor acts as a short circuit ( considering switch is closed since a long time, that will be a steady state condition for the inductor). Because of that, 20 ohm resistor in parallel to inductor will get short circuit. And overall, there will be a short circuit in parallel to current source. So, 20 ohm resistor, which is connected in parallel to current source will also get short circuited. And therefore, entire 2.5 A current will flow through short circuit. Or in other words, 2.5 A current will flow through the inductor. So, we can say that, at t=0-, inductor current is 2.5 A. I hope, it will clear your doubt.

[@taruntej7867]

@@ALLABOUTELECTRONICS thanks alot sir ❤

[@Riya___kalita]

What if the capacitor has some initial charge and the switch is closed at t=0

[@ALLABOUTELECTRONICS]

If it has some initial charge, then it will act as a voltage source at t =0 +.

[@imSurajsingh24]

well explanation ️👍❤️

[@Hh-ze4vm]

minus 2.5 kese explain toh kro pura

[@MohitVerma-zp2ck]

Super ....👌👌👌👌👌👌👌👌

[@pks2089]

Draw Req arrow from right to left.

[@sangameshmpatil4789]

sir what is the o/p if we connect current source to rc ckt

[@ALLABOUTELECTRONICS]

I hope you are talking about the circuit in which current source is connected in parallel with R and C. (i.e parallel RC circuit). Well, in that case, the capacitor voltage equation will remain same, Vc(t)= V([1-e^(-t/RC)] ; where V is the final value or voltage across capacitor in steady state. Please try it by yourself by applying KCL in such circuit.

[@neerajbahuguna7150]

Req and ceq nikalne k liye t =infinity pe nikalenge ya t =0

[@ALLABOUTELECTRONICS]

Just draw the circuit at t=0+. And for that circuit, find the Ceq and Req.

[@abhivichare713]

@@ALLABOUTELECTRONICS ok then at 7:00 Req would become 20k as at t=0+ only 20k is in circuit as capacitor is short circuited.

[@robertlake2753]

Got a circuit you wanna build? Test it out here first. Arrive at: 'Circuit Solver' by Phasor Systems on Google Play.

[@shashankcholleti2003]

sir for practicing more problems not only for this topic for imp.topics post some WORKSHEETS in the description with solns it will b more hlp ful for students like me

[@ALLABOUTELECTRONICS]

There is a seperate channel for the questions. Please check ALL ABOUT ELECTRONICS- QUIZ. You will find the different playlist. ( You may check Network Analysis playlist)

[@rishabhsharma7701]

@@ALLABOUTELECTRONICS thank you sir ...🤩

[@electricalsujitgope]

You are god 🙏

[@amierulhaqimi3428]

Mantap sir 👍👍👍

[@arunchand201]

nice explanation brother

[@venkatalokesh1117]

Sir I want answers for the extra examples

[@luvchugh616]

In question no.1 while finding Reqvivalent we consider 20kohm vertical resistor short and only 20k ohm hoz. Resistor is being considered . There is any rule while finding R eqvivalent ki parallel resistor get short While comparing this with question 3 while finding R eqvivalent we don't consider left most resistor short why?????

[@ALLABOUTELECTRONICS]

The equivalent resistance is found by finding the Thevenin's equivalent resistance across the capacitor. So, for that, all the independent voltage sources are considered as a short circuit and all the independent current sources are considered as an open circuit. That's why in the first example, 10V voltage source is shorted. And then after, two 20K resistors are in parallel. So, Req= 10K. In the third example, as there is a current source, it was considered as an open circuit while finding Thevenin's equivalent resistance across the inductor. I hope it will clear your doubt.

[@muddamsravanthi4975]

Thank you so much sir

[@hongjiaoqiang5090]

super helpful!!!

[@PavelowB99]

fantastic!

[@hanupawandwivedi6613]

20 kohm is short circuited? Can anyone tell?

[@ALLABOUTELECTRONICS]

In the first example, the voltage across the capacitor is zero at time t= 0-. And capacitor opposes the instantaneous change in the voltage. That means Vc(0+) = 0V. Hence, at t= 0+, the capacitor can be replaced by the short circuit. And as 20k ohm is in parallel with the capacitor, it will also get short-circuited at time t= 0+. I hope it will clear your doubt.

[@yasso3319]

how did you go from 40 to 25?? someone explain please

[@ALLABOUTELECTRONICS]

If you observe 40 is actually 40 ms, that is 0.04 seconds. So, 1/0.04 = 25 I hope it will clear your doubt.

[@yasso3319]

ALL ABOUT ELECTRONICS yes thank you