Thevenin & Norton Examples - Thevenin Equivalent Circuit Theory - Part 2

[soccerfan800]

can we use nodal analysis instead to find voc

[sammybriz]

Thank you so much - this has helped me a great deal with my engineering exam!!!

[fafase]

Second video and already 3 mistakes (if not more).Now if people mention mistakes, there are 2 possibilties, either you are wrong or you are not clear enough so they think you are wrong. Also, if you are not sure about it don't go and post videos. People rely on you for learning because you claim you know and name yourself as "Dr" J. You were not forced to do the vids, if you can't then don't.

[SadiaKhaf]

U made some mistake but still it was helpful.

to calculate short circuit current (current through 15ohm resistor) we can simply do a two step solution.

First:5, 10 & 15 are in parallel.leave 15 separate and calculate equivalent resistance of 5 & 10. It comes out to be (5*10)/(5+10)=3.33

Second:Apply current divider to 15&3.33 n you will get the answer.

(3.33/(3.33+15))*3=0.545A

[nugg69]

not the best explanation on norton

[etacsik]

i should teach u how to calculate the equivalent resistance

[etacsik]

not good explain

[okman1234567]

Dr. J i applied this method, which differentiates with the textbook i have, and the problem is exactly the same instead with different numbers, but the book indicates a different R_T.

If you want to take a crack at it, the format of the circuit is the same. But the V=10. R1=5=5. R2=20 which is equal to 10 ohms in your example. R3=10 ohms which is 15 in yours. I did exactly what you did and the answer came as 25, but the book indicates 14 ohms. any suggestions?

[hazemgoal]

thanks dr

[twinkle152000]

This video helped me thank you.

[basa9001]

thanks man..........now its much much clearer in my head......i have a bad textbook....but u helped alot..........thanks man we want to see more videos if u can.....

[tyfa3]

Thank you very much

[xJeggernautx]

Dr.J I think you may have made a mistake when calculating the current for the 5 Ohm resistor.

Yes the 10 Ohm and 15 Ohm resistor in parallel will comprimise a single 6 Ohm resistor in parallel with the 5 Ohm Resistor. But you assign the smaller portion of the 3A current towards the smaller resistor (5 Ohm branch instead of the 6 Ohm branch)

1.36A should run down across the 5 Ohm Resistor while 1.63A should run towards the next node and split accordingly between the 10 and 15 Ohm Resistors.

[drjctu]

@xJeggernautx thx for the feedback. I will check it out after I finish grading the finals this week...thx again...Dr J

[SadiaKhaf]

@xJeggernautx

larger amount of current flows through smaller resistor n small current goes towards higher resistance.here we have one resistor of 5 ohm n other is equivalent of 10&15 which comes out to be 6 so it is greater than 5.hence smaller portion of current i.e 1.36 flows through it and 1.63 flows through smaller 5 ohm resistor.

[aprilzLuV]

u did the calculation wrongly for the current divider rule.....

am i right???

it is not 5 over the sum but the sum over 5 the multiply by 3A

[drjctu]

@aprilzLuV Since the current divider divides the incoming current, the current through each of the resistor has to be less than the incoming current. Also, the Thevenin resistance can also be viewed as the Rth when the sources are removed. In this case, short the voltage source. So 5 ohm in parallel with 10 ohm is in series with the 15 ohm or an equivalent resistance of 18.33 ohms across the terminals A and B. This yields the same result in the video. Hope this helps. Dr J

[aprilzLuV]

@drjctu owh yeah i juz realised it ..:D thx.....ur vids helps a lot....!!thxn_n

[darkmahnMX]

@aprilzLuV noup u r wrong xD

[bezaldo7]

Amazing video!!!but i have a question; can we find R(th) without calculating i(sc)?Thank you Dr.J

[drjctu]

Yes!. You need to remove the independent sources (short voltage sources, open current sources). Then, calculate the equivalent resistance between the two terminals.

Hope this helps! Dr J

[socio220]

thanks a lot

[huzu1019]

thank You. ece 111 should be easier now even though our professor is used to teaching 400 level classes where kids get most of this.

[CraigusMalaigus]

Great video. I can understand Thevenin and Norton circuits much better now. Thanks!