I’m probably a psychopath but I’m graduated and the day before I have something big at work like an important meeting or presentation I come back to videos I used to watch falling asleep before exams during my final cram. It’s extremely relaxing and keeps me fresh on topics I don’t use often
Thank you sir, really helped me a lot in our exam, but one thing got my head hurts when I encountered a signal with gain and decay can you do some vids about it with a calculus approach. Thank you in advance. 💓
Your analysis is spot on but the motivation for rms goes like- you want a voltage value that is representative enough for energy transfer- heat in particular. For a resistor at any instant, power = v× current This P=vxv/R =(v)squared/r. Calculate average value of power over a full cycle- thats where the intergration and division by periodic time comes in. The root now comes out of need to come up with a representative voltage for power purposes. Hence root mean square
Thanks for the kind words!. I do have a playlist on AC circuits. Many of the problems from the playlist were from an assignment i gave to my college class a couple of years ago.
Thank you for the video. However, for the square wave, you don't cover the situation when the square wave becomes bipolar AND keeps the same amplitude change (+/- Vmax centered on zero). It is for this case that I am really confused because it seems that the Vrms is not the same yet the |Vavg| across the load is staying the same. In your example the |Vavg| is Vmax/2 and the same in my scenario. Any help would be appreciated.
Hey physics ninja , thank u for the awesome vid. Really helped . I just wanted to know the RMS and AVERAGE values for the second form of square wave!!! and brief explanation if possible ? Thank u ....love from india
So, what do we learn? Period doesn't matter? So, I can take the RMS of seismic waves and not have to worry about the period? Just wanting to make sure I understand it. I can have a user specified time window, square the timeseries, take the mean and then the square-root?
Keep in mind that my signals were very simple and always repeatable. I was able to get away with only integrating over 1 cycle. If you have a signal with many unknown frequencies you need to make sure that your length of integration is long enough to capture the low frequency content of your signal, other your RMS measurement won't be very good. Longer acquisitions will always be better but they take more time.
An alternating current varying sinusoidally with a frequency of 50 Hz has a RMS value of 20 A. Write down the equation for the instantaneous value and find this value at: (a) 0.0025 s (b) 0.0125 seconds after passing through a positive maximum value. (c) At what time measured from a positive maximum value, will the instantaneous current be 14.14 A?
One thing to be very careful with is how the square wave is defined. In my video i use a square wave that doesn't switch polarity - it's either V_max or 0. In that case it's the same as the sinusoidal. If the square wave switched between V_max and -V_max then you'd find that the V_RMS=V_max.
Hello sir , Could you please solve this question: A seesaw is 10m long , if F1=20N and F2=5N , Where will you put the pivot to make this seesaw balanced ? ( find L1 and L2 ) ....Thanks
well .707 is the difference in heating energy from dc and ac using 1 amp. DC is 100 Ceslsius and AC is 70.7. and 1.414 is the amount needed to match the 100% of DC. Thus .707 and 1.414 I effective is eg ma2 x 1.414 and I rms i ma2 x .707
Current in a resistor is a start-stop motion of conduction band electrons due to their collision with the rocking lattice ions, and this causes a resistor with a sinusoidal voltage applied, to produce heat. The polarity reversals of an applied sinusoidal voltage (with the direction reversals of the applied electric field) do not affect electron collisions with the lattice ions. Electrons colliding with lattice ions from either direction will continue to produce heat and there is no cancellation of the heat developed! Mathematically, the average value of a sinusoid is zero, and so, the average value of the current will also be zero. The average values cannot therefore represent the heat developed in a resistor with a sinusoidal current. A resistor cannot develop heat due to a current in one half-cycle and then cool itself by a like amount of heat during the next half-cycle! It develops heat either way whether the current is positive or negative. The lattice ions vibrate from collisions irrespective of the directions in which the electrons collide with them. Therefore, since the average value is zero, it necessitates the use of the root-mean-square values of the voltage and current to compute the power, which is a statistical measure of the magnitude of a varying quantity and is the square root of the arithmetic mean of the square of the sinusoidal function. Electrostatics and circuits belong to one science not two. To learn the operation of circuits it is instructive to understand Current, the conduction process, resistors and Voltage at the fundamental level as in the following two videos: i. ua-cam.com/video/TTtt28b1dYo/v-deo.html and ii. ua-cam.com/video/8BQM_xw2Rfo/v-deo.html It is not possible in this post to discuss in more detail average and rms values. The last frame References in video #1 lists textbook 4 which discusses in detail using a unified approach sinusoidal voltage, current, their average and root mean square values.
I’m probably a psychopath but I’m graduated and the day before I have something big at work like an important meeting or presentation I come back to videos I used to watch falling asleep before exams during my final cram. It’s extremely relaxing and keeps me fresh on topics I don’t use often
this is genius
Thank you for an comprehendible explanation. I finally get why those calculus classes were necessary!
Thank you, was really helpful. much appreciated
Thank you so much! Very clear explanation! I learned the term in my chemistry class first and then physics, but no one explained what it is!
Thank you for your explanation was so clear.
Excellent Video, really appreciate for the great detail explanation.
Thank you for this wonderful explanation
Thanks very much - I finally understand it.
Thank you, It was really helpful.
Very clear! Thanks a lot
Thank you. You cleared my doubt.
You are simply the best.
Sir ..thanq ..I'm very thankful to you...
Thank you sir, really helped me a lot in our exam, but one thing got my head hurts when I encountered a signal with gain and decay can you do some vids about it with a calculus approach. Thank you in advance. 💓
I feel like becoming a shinobi on solving these problems
Thanks a lot amigo..
Your analysis is spot on but the motivation for rms goes like- you want a voltage value that is representative enough for energy transfer- heat in particular. For a resistor at any instant,
power = v× current
This P=vxv/R
=(v)squared/r.
Calculate average value of power over a full cycle- thats where the intergration and division by periodic time comes in.
The root now comes out of need to come up with a representative voltage for power purposes. Hence root mean square
Wonderful!
Greetings from Eastern Arabia
How would you incorporate a DC offset value into these formulas? As well does frequency even matter when it comes to finding Vrms?
Thanks for an excellent explanation. I found it very helpful. I hope to see more videos of AC analysis from you.
Thanks for the kind words!. I do have a playlist on AC circuits. Many of the problems from the playlist were from an assignment i gave to my college class a couple of years ago.
Thankyou, thankyou, thankyou, thankyou so much, legit life saver
Thank you for the video. However, for the square wave, you don't cover the situation when the square wave becomes bipolar AND keeps the same amplitude change (+/- Vmax centered on zero). It is for this case that I am really confused because it seems that the Vrms is not the same yet the |Vavg| across the load is staying the same. In your example the |Vavg| is Vmax/2 and the same in my scenario. Any help would be appreciated.
Thank you so much P.N.
+
15 guys couldnt get this water clear explanation
Hi Ninja, I like your lecture
Thank you sir
Appreciate it 👍🏻
The sinusoidol signal is not depending on the frequency, is the square signal depending or not depending on the frequency?
Thanks a lot
Thanks sir😁
Sir the dt should be dwt because if there is only dt then we also divide the angle of of sin mean w
what if you had a dc offset?
Hey physics ninja , thank u for the awesome vid. Really helped . I just wanted to know the RMS and AVERAGE values for the second form of square wave!!! and brief explanation if possible ? Thank u ....love from india
For the second case Vrms=Vmax and the average would be 0.
@@PhysicsNinja yes...I got it ..I could derive it using the method u taught ...thank u!!!
So, what do we learn? Period doesn't matter? So, I can take the RMS of seismic waves and not have to worry about the period? Just wanting to make sure I understand it. I can have a user specified time window, square the timeseries, take the mean and then the square-root?
Keep in mind that my signals were very simple and always repeatable. I was able to get away with only integrating over 1 cycle. If you have a signal with many unknown frequencies you need to make sure that your length of integration is long enough to capture the low frequency content of your signal, other your RMS measurement won't be very good. Longer acquisitions will always be better but they take more time.
The square formula is also valid for waves that does not have a 50% duty cycle ?
Yes
it the best rms i have seen today
Bro. This guy is the more vively version of the school teacher of south park
Can the instantaneous magnitude on the wave be negative?
Yes!
thank thank you saved my ass great explanation
An alternating current varying sinusoidally with a frequency of 50 Hz
has a RMS value of 20 A. Write down the equation for the
instantaneous value and find this value at:
(a) 0.0025 s
(b) 0.0125 seconds after passing through a positive maximum value.
(c) At what time measured from a positive maximum value, will the
instantaneous current be 14.14 A?
So square waveform has same rms voltage as sinusoidal?
One thing to be very careful with is how the square wave is defined. In my video i use a square wave that doesn't switch polarity - it's either V_max or 0. In that case it's the same as the sinusoidal. If the square wave switched between V_max and -V_max then you'd find that the V_RMS=V_max.
@@PhysicsNinja what about the Vavg?
is it 0
then F.F is undefined?
Sir l like your way of teaching thanks for your kindness
Sinewave of your audio volume is a little distracting but great walkthrough. Thank you.
Sir how to calculate sawtooth RMS for 2 cycles, because the answer is not matching with that of 1 cycle
2=1
@@PhysicsNinja I don't get it??
wait a minute... what is calculus?
Hello sir ,
Could you please solve this question:
A seesaw is 10m long , if F1=20N and F2=5N , Where will you put the pivot to make this seesaw balanced ? ( find L1 and L2 ) ....Thanks
fuck you
Is omega=2pi or Omega=2pi * frequency?
Second one
well .707 is the difference in heating energy from dc and ac using 1 amp. DC is 100 Ceslsius and AC is 70.7. and 1.414 is the amount needed to match the 100% of DC. Thus .707 and 1.414 I effective is eg ma2 x 1.414 and I rms i ma2 x .707
Current in a resistor is a start-stop motion of conduction band electrons due to their collision with the rocking lattice ions, and this causes a resistor with a sinusoidal voltage applied, to produce heat. The polarity reversals of an applied sinusoidal voltage (with the direction reversals of the applied electric field) do not affect electron collisions with the lattice ions. Electrons colliding with lattice ions from either direction will continue to produce heat and there is no cancellation of the heat developed!
Mathematically, the average value of a sinusoid is zero, and so, the average value of the current will also be zero. The average values cannot therefore represent the heat developed in a resistor with a sinusoidal current.
A resistor cannot develop heat due to a current in one half-cycle and then cool itself by a like amount of heat during the next half-cycle! It develops heat either way whether the current is positive or negative. The lattice ions vibrate from collisions irrespective of the directions in which the electrons collide with them. Therefore, since the average value is zero, it necessitates the use of the root-mean-square values of the voltage and current to compute the power, which is a statistical measure of the magnitude of a varying quantity and is the square root of the arithmetic mean of the square of the sinusoidal function.
Electrostatics and circuits belong to one science not two. To learn the operation of circuits it is instructive to understand Current, the conduction process, resistors and Voltage at the fundamental level as in the following two videos:
i. ua-cam.com/video/TTtt28b1dYo/v-deo.html and
ii. ua-cam.com/video/8BQM_xw2Rfo/v-deo.html
It is not possible in this post to discuss in more detail average and rms values. The last frame References in video #1 lists textbook 4 which discusses in detail using a unified approach sinusoidal voltage, current, their average and root mean square values.
thank you so fcking much :)!
You got this!
asalm alaykom
why don’t we say that the RMS value of the square function = since there is no negative part in it?
12:38 Vrms=V
Physuys ninja jyst fuxing scammed me:rage: :rage: :rage: :rage: , thanks god for johan he is da best -Eivind and Baksel
Stay calm bro, it’s just physics.