Electrical Engineering: Ch 3: Circuit Analysis (11 of 37) Mesh Analysis w/ Voltage Sources: Ex. 2

In this video I will find the currents of a circuits with 2 current sources using mesh analysis.

Next video in this series can be seen at:

[firdauspuzi]

What is the answer if we use 45 V instead of 15V like in the video? Anyone knows? I got i1= 3A, i2= 0.75A

[gutierrezmarjassonpatrick]

i think it is 45v . not 15v. according to ur diagram :)

[noigilerkcufi]

I used 45V for a laugh, when I compared it with your circuit it helped me further understand the roles of elements within a circuit.

Cheers pal.

.

[copperboy]

you make hard things simple...you are amazing!!

[lehlohonolodiholo]

I got my I1=3 and I2=0.75 and they prove kvl law when I subtitude them

[mareklewanski]

Hello Mr. Michel van Biezen. If I assumed voltage on left side 45 V I received I1 opposite direction you marked 3 A, i3=2, 25 A opposite direction you marked and i2=0.75A same direction. Which is good acc to KCL 🙂 We all are human beings 🙂

[katharos]

Sir can I ask why the 9 ohm resister had a voltage drop if i2 and mesh 2 are on opposite directions?

[yc]

Thanks sir great explanation, but are we not supposed to find the current through the 4ohm and 3ohm resistor

[manishakundu]

sir dont we need to find out the branch currents through the 3ohm and 4ohm resistances? as far as i understood, they should be equal to I2 and I1 respectively, is that correct?

[richardnewens]

For the chosen currents why isn't mesh 2 = 12(I2-I1)+(9)I2-18+(3)I2 ?

[Octavio_Jorge]

Great explanation professor!! but i have one doubt, how should we do to find the voltage on the third branch the middle one?

[bozokymarton]

Dear Professor,

I would like to have a question:

I assumed I2 in the other direction what you did, and I think I wrote a bad equation:

15 - 2*(I1) - 12*(I1+I2 ['plus' because they have the same direction on that specific branch]) -4*(I1) =0

I ended up getting 2 Ampers for I1 and -1.75 for I2, so I clearly made a mistake.

Could you please explain how should I write equations for branches when I assume multiple currents going on them in the same direction?

[murdakcreatives]

Is it required for the two mesh to move in the same direction? Or can it be opposite?

[manuelsone]

On the screen you had a voltage source of 45 but your equation showed 15

[francescachery]

Hi Michael, why is there a voltage rise at the 12 OHM resistor for mesh 2? Shouldn't it be a voltage drop since the loop in mesh 2 is going in the opposite direction as i3?

[TheYazeed]

If we assumed a counterclockwise direction for I2 would the solution stay the same?

[cena]

I have a doubt in MESH 2 eq. should not it be 0=18v-3i2-12( i2- i1)-9i2.

[youtubemaster]

In 9 ohm resistor in mesh 2 have brach current direction opposite to mesh current so should it not be positive voltage.

[minhasmustafa]

why did you not calculate the branch currents through 3-ohm and 4-ohm resistors?

[tundeoriyomi]

What if I decide not to change the direction of the current, i2?