Electrical Engineering: Ch 11 AC Circuit Analysis (10 of 55) Nodal Analysis Ex. 1

In this video I will find the voltage, V=?, using the nodal analysis method, at the node given an input (source) voltage and another source voltage within the circuit.

Next video in this series can be seen at:

[gzik]

not gonna lie, these lectures helped me A LOT

[guilhermebraga]

This man is a legend, thanks for the amazing content!

[amramjose]

Excellent example professor. I learn with every video.

[valonyaver]

When do we know when to subtract or add the 180 to the angle to switch the mode of the result? Is it only if a particular i or v that we find is negative?

[rationalthinker]

For your answer V = Magnitude 125, angle -153.6 degrees....I was curious about the magnitude. Our source voltage has a magnitude of 120, is it possible for other points on the circuit to be at a higher potential than our source? I wasn't sure if the addition of a current source could affect the outcome. Thanks!!

[batuhanbilgin]

Sir, I am confused If we have a more complex circuit how would we able to find nodes?

[balayoganarendra]

Thanks sir, can you solve a study state AC analysis circuit with Laplace’s transform

[Al-amin]

Thank you so much sir, it's help me a lot .

[BusterrHimen]

Wonderful series but it gets very difficult to follow along at points when you start doing steps in your head :( for the future can you please take the extra time and just explain like what happened at 3:20, I know it can be simple to others but when learning this material for the first time, those steps aren't yet inherent to someone learning! Thanks for everything either way!

[hugomax]

How can V/-j30 ever become positive V(j0, 003) ?

[nigelvanlaethem]

For this method I found it helpfull to work with symbols untill the V is seperated.

[joypalit]

sir the calculations are bugging me a lot! my process is correct but i cant match my answers

[alinoory]

prof. Biezen, can you please tell me when we take the sine of the angle or the cosine of the angle? I'm still confused with that. Also how do you know what is the angle if it was 30 or 90 without doing any calculations? thanks in advance for the great work.

[simgauvin]

Why does the ''r'' and the angle is different using (-3.19 - j4.78)/(0.04 + j0.023) than when we use -(3.19+j4.78) / (0.04 + j0.0.23) ?


both numerator are technically equal,
but when I use (-3.19 - j4.78) I ultimately end up with 125 angle 26.38 degrees (sqrtroot((-3.19)^2 + (-4.78)^2) = 5, 75)
(tan^-1 (-4.78/-3.19) = 56.28 degrees )

5.75/0.046 =125 (positive)
56.28-29.90 = 26.38 degrees

which would be 125 angle 26.38

instead of the 125 angle 206.38 degrees that you ended up with...

the signs for the r calcultion are what is bugging me I think.

[rabbitazteca]

how will we know where to place the ground? Will it always be in the wire wherein the total current is going back to the voltage source?