I needed this. What an excellent teacher. Please make more videos! I would like to see more basic AC circuits like this calculating RMS voltage across and through resistors.
If anyone could answer this I'd be eternally grateful. What I fail to understand is with this being an AC circuit, when he says that voltage and current on the resistor are in phase, wouldn't that only be true half of the time(on the pos or neg cycles depending on which side the resistor is on) or does the RMS conversion render that irrelevant? Just thinking about this, when current is flowing in a way that it hits the inductor first, wouldn't that throw the voltage and current out of phase for anything else that happens to be in series with it?
The current thru a resistor and voltage drop are always in phase and all the time. It has nothing to do with how a resistor is placed in the circuit. All that matters is that it's a resistor. Same thing for inductors and capacitors and their leading and lagging voltage effects wrt current. With resistor there or no leading and lagging effects because current and voltage are always in phase. Think of phase shifting (as accounted for with expression for Impedance) as a "local" or relative quantity. It has nothing to do with the global yet arbitrary phase angle of the ac source (either current or voltage) in the circuit. The only reason the triangle form by impedance is oriented so reactance is always vertical is by assigning the global phase angle of the ac source such that the reference quantity (in case of series the reference quantity is current) has a phase angle of 0. If the ac source is the same as the reference quantity then the sources global phase angle is assumed to be 0 degrees for an ac source applied as a cosine in the time domain. If the ac source applied is the same as the reference quantity but expressed as a sine function in the time domain then the global phase angle is - pi / 2. This is done so the orientation of the right triangle where resistive effects are horizontal is valid. That's the reason he doesn't assign a phase angle in this case where the independent ac source is also non-reference quantity (I.e. sinusoidal voltage). That gives him the liberty to show the analysis in graphical form as a triangle where resistive effects are horizontal at 0 degrees and reactance at 90 degrees to form the sides of the triangle. If the ac independent source was sinusoidal current then the phase angle would be assumed to be 0 and expressed as cosine in the time domain . I'm learning from this instructor as well but I also know there's a more general underlying theory as well and I'm reconciling both the more practical side / graphical approach he teaches (and is good at) and the theoretical side that I've never seen him mention but that is the basis for the approach he teaches.
Hi good morning sir This is Mardorine writing from Cameroon. My question is if the value of the inductor or that of the active reactance was not given. How then will the inductance be calculated ? Given that the angle has been provided ?
My problem does not include the resistance of the resistor or the total voltage, I’ve been searching the Webb for hours trying to figure out how to solve this cursed problem.
It would be good if he showed how the impedances are actually complex numbers derived from ohms law for operation of resistor and inductor in steady state ac circuit. That would take the analysis to the theory that forms the basis for using Pythagoras to add the impedances together to get the current (the reference quantify in case of 2 components in series) via ohms law. I'm surprised he didn't calculate the phase angle of the applied voltage. He wanted the phase angle for the current derived from ohms law to be 0. He's doesn't want to get too theoretical but it puts meat on the bone so to speak in ac circuit analysis. If theory is to be avoided then the vertical component of impedance can be thought of as being derived from considering what effect does the inductor have on voltage drop when subjected to alternating current? Answer: the voltage drop sinusoidal leads the current sinusoidal by 90 degrees and so the impedance for inductor is vertical (in the up sense) relative to resistor's horizontal (in the to the right sense) impedance (no phase shift effect of resistor on voltage). In analysis of parallel circuit the voltage drop would be assigned as the reference sinusoidal quantity @ 0 degrees phase and so represented in the horizontal direction. But now the non-reference current sinusoidal quantity lags the reference quantity(voltage) and so the effect of inductor Impedance is still vertical but in the downward sense because current is derived from dividing voltage reference sinusoidal quantity by inductor Impedance. In summary In series ac circuit analysis (where current is the reference quantity @ 0 degree phase angle) the voltage leading effects of inductor prevail. In parallel ac circuit analysis (where voltage is the reference quantity @ 0 degree phase angle) the current lagging effects of the inductor prevail. So to recap what's be emphasized here is more of what may be in the practical / lab side of a college level course study of ac circuit analysis. The other side is the theoretical / lecture side of the course study that introduces the phasor approach (involves a look at ohms law with complex numbers and the representation in the complex plane) to which in turn is derived from analysis in the time domain. The phasor is a complex plane representation of just the phase and magnitude aspect of the sinusoidal quantities in the time domain. The only time frequency is considered is to calculate the magnitude of the impedance for capacitor and inductor.
This guy knows how to teach, a very rare gift these days.
This is easily the best video on RL circuits on youtube
I understood more in this 12 min video than a whole semester I just did in college...its all about the teacher delivery!!
i like your speed-ups. takes the boring out. great vids.
I needed this. What an excellent teacher. Please make more videos! I would like to see more basic AC circuits like this calculating RMS voltage across and through resistors.
You saved my skin the night before deadline, thanks. Very clear explanation.
Very well explained, one of the best videos I've seen so far!
ELI the ICE man. Outstanding instruction Dave!
"Two Pi Fo Life" I laughed way to hard at this. I will never forget the inductive reactance formula now.
Second level electrican apprentice here. Had a lession in class today about this. Combined with this very good video the light bulb is finally on 😂
It so simple when you explain it. Thank you for saving me Dave!
I have an circuit analysis labratory exam in a few hours. It'll be so helpful. Thanks so much
Dave, you are an excellent instructor.
Thank you. Your explanation unlocked all my concerns. Very simple and easy to understand.
This is pure GOLD!! Glad I stumbled across it just surfing ...
Sir this is just owsome . I was struggling learning this topic but you made this so much exciting ....thank you ...God bless u ..lovely
This guy explains this stuff so simple.
thank you very much ! I was stuck on this chapter
These videos are so easy to follow
It really works! I just forgot how or when I needed to use it.
Thanks a lot for this video. Sir.
Mr Gordon we don't just plus'em"
Me 🤯
You are saving my life
1:17 - two pie for life
Good job thecher 👏👏👏👏
Excellent…. Thank you
You are amazing ❤
Keep it up, Teach.
bro you are the best holy shitttt
I would like you to ask something. If question asks that instantaneous values of the voltage across the Vr and VL, will we apply the same steps?
Awesome videos
Cum aflam inductanta unei bobine? Mulțumesc!
Thank you !
Thanks so much !!!!
where can i buy the hand calculator @5:12? ;)
Thank you sir
Why I feel this is organic chemistry teacher, same ah d writing say way of speaking same voice
If anyone could answer this I'd be eternally grateful.
What I fail to understand is with this being an AC circuit, when he says that voltage and current on the resistor are in phase, wouldn't that only be true half of the time(on the pos or neg cycles depending on which side the resistor is on) or does the RMS conversion render that irrelevant?
Just thinking about this, when current is flowing in a way that it hits the inductor first, wouldn't that throw the voltage and current out of phase for anything else that happens to be in series with it?
The current thru a resistor and voltage drop are always in phase and all the time. It has nothing to do with how a resistor is placed in the circuit. All that matters is that it's a resistor. Same thing for inductors and capacitors and their leading and lagging voltage effects wrt current. With resistor there or no leading and lagging effects because current and voltage are always in phase.
Think of phase shifting (as accounted for with expression for Impedance) as a "local" or relative quantity. It has nothing to do with the global yet arbitrary phase angle of the ac source (either current or voltage) in the circuit.
The only reason the triangle form by impedance is oriented so reactance is always vertical is by assigning the global phase angle of the ac source such that the reference quantity (in case of series the reference quantity is current) has a phase angle of 0.
If the ac source is the same as the reference quantity then the sources global phase angle is assumed to be 0 degrees for an ac source applied as a cosine in the time domain. If the ac source applied is the same as the reference quantity but expressed as a sine function in the time domain then the global phase angle is - pi / 2.
This is done so the orientation of the right triangle where resistive effects are horizontal is valid.
That's the reason he doesn't assign a phase angle in this case where the independent ac source is also non-reference quantity (I.e. sinusoidal voltage). That gives him the liberty to show the analysis in graphical form as a triangle where resistive effects are horizontal at 0 degrees and reactance at 90 degrees to form the sides of the triangle.
If the ac independent source was sinusoidal current then the phase angle would be assumed to be 0 and expressed as cosine in the time domain .
I'm learning from this instructor as well but I also know there's a more general underlying theory as well and I'm reconciling both the more practical side / graphical approach he teaches (and is good at) and the theoretical side that I've never seen him mention but that is the basis for the approach he teaches.
Thx Mr
Hi good morning sir
This is Mardorine writing from Cameroon.
My question is if the value of the inductor or that of the active reactance was not given.
How then will the inductance be calculated ?
Given that the angle has been provided ?
My problem does not include the resistance of the resistor or the total voltage, I’ve been searching the Webb for hours trying to figure out how to solve this cursed problem.
This was perfect
It would be good if he showed how the impedances are actually complex numbers derived from ohms law for operation of resistor and inductor in steady state ac circuit. That would take the analysis to the theory that forms the basis for using Pythagoras to add the impedances together to get the current (the reference quantify in case of 2 components in series) via ohms law.
I'm surprised he didn't calculate the phase angle of the applied voltage. He wanted the phase angle for the current derived from ohms law to be 0.
He's doesn't want to get too theoretical but it puts meat on the bone so to speak in ac circuit analysis.
If theory is to be avoided then the vertical component of impedance can be thought of as being derived from considering what effect does the inductor have on voltage drop when subjected to alternating current? Answer: the voltage drop sinusoidal leads the current sinusoidal by 90 degrees and so the impedance for inductor is vertical (in the up sense) relative to resistor's horizontal (in the to the right sense) impedance (no phase shift effect of resistor on voltage).
In analysis of parallel circuit the voltage drop would be assigned as the reference sinusoidal quantity @ 0 degrees phase and so represented in the horizontal direction.
But now the non-reference current sinusoidal quantity lags the reference quantity(voltage) and so the effect of inductor Impedance is still vertical but in the downward sense because current is derived from dividing voltage reference sinusoidal quantity by inductor Impedance.
In summary
In series ac circuit analysis (where current is the reference quantity @ 0 degree phase angle) the voltage leading effects of inductor prevail.
In parallel ac circuit analysis (where voltage is the reference quantity @ 0 degree phase angle) the current lagging effects of the inductor prevail.
So to recap what's be emphasized here is more of what may be in the practical / lab side of a college level course study of ac circuit analysis.
The other side is the theoretical / lecture side of the course study that introduces the phasor approach (involves a look at ohms law with complex numbers and the representation in the complex plane) to which in turn is derived from analysis in the time domain. The phasor is a complex plane representation of just the phase and magnitude aspect of the sinusoidal quantities in the time domain.
The only time frequency is considered is to calculate the magnitude of the impedance for capacitor and inductor.
okay, buddy. 🙄
Thankyou
👏👏👏🙏🙏❤❤
Nice
Problem solved 😁😁
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I like the sound
@@karinaburgess3989
Good for you