Physics 49 RCL Circuits (2 of 13) Complex Numbers

[@Lexyvil]

The best teacher I currently know. I was stuck trying to understand impedance and complex numbers for days. Amazing explanation, professor!

[@MichelvanBiezen]

Great to hear! (I went to school in Edmonton a LONG time ago)

[@zeyadramadan8759]

Best teacher ever. Please keep it up. You are really simplifying things to us.

[@MichelvanBiezen]

Thank you! 😃

[@yuhema9779]

Sir you are my hero!!! I am taking intro to computer and electrical engineering this semester and your videos on circuits are of great help!!!!!!!

[@MichelvanBiezen]

Glad to hear it. Keep up the good work!

[@rievezahl]

Thanks for this pristine, super educative presentation! Even though the bar of your competition here on youtube is rather low, its not just a little better than any other video, its like exactly what i hoped to find! keep up the great work!

[@MichelvanBiezen]

Thank you

[@frankreiserm.s.8039]

You are the most understandable person that discusses RCL circuits. Unlike general matnematics, use j to represent an imaginary number in electronics: j20

[@Dog-ct8hs]

j is common in EE.

[@yourlordandsaviouryeesusbe2998]

You're a God, Mr. Biezen

[@MichelvanBiezen]

You can be assured that I am not. Just a man trying to do his part in the world.

[@tommaher6978]

Really good . And slowly explained with easy to follow steps. Thanks

[@MichelvanBiezen]

Thank you. Glad you found our videos! 🙂

[@deustitties3589]

How the hell am I finding your videos on RLC circuits only now. I've been a subscriber for quite some time and all I find on KZbin when it comes to RLC are mostly some hard to understand indians. KZbin's algorithms are completely broken. Your lectures are super helpful.

[@MichelvanBiezen]

The best way to find them is to go to the home page on this channel. All of the playlists can be easily found from the home page.

[@shreyasdeshpande3042]

Very good teaching sir👏 Respect from India.

[@MichelvanBiezen]

Welcome to the channel!

[@hasanyahya9171]

You had presented a whole of subject clearly. However as a beginner I am still doubtful about RL. Does it (RL) alway exist in any inductor? Is this cause of the nature of any conductor as it long enough ? Thank you professor.

[@MichelvanBiezen]

Yes, every inductor has inductance and has some internal resistance if there is no external resistor. Sometimes we ignore the internal resistance in order to show a particular property or law. Note that inductors oppose a CHANGE in current.

[@midnightson787]

Excellent video thanks

[@yajatdalal1823]

Great Explanation 👍

[@jetlinux]

Brilliant sir!

[@MichelvanBiezen]

Thank you. Glad you liked it.

[@mahmoudeldesokey147]

Please sir, what do we mean by representing reactance And resistance as phasors? I am confused because representing them as phasors means they will have instantaneous values as these phasors rotates And i think that reactance And resistance are constants.

[@MichelvanBiezen]

When they are represented by phasors, we recognize that the voltage and current is time variant and the phasors rotate per wt. The phase angle for each component indicated the phase difference between the voltage and current for each component, which in the case of a resistor is zero.

[@carultch]

Phasor is a compound word of phase and vector. Sine waves have the general equation of Y=A*sin(w*x + phi). A vector of magnitude A, and direction phi as an angle from the positive real number axis, is how we keep track of both the amplitude A and phase offset phi, when we have multiple sine waves at play in a given problem. Think of a phasor as a vector that is continuously rotating around the origin. The projection onto the real axis indicates the real time value of the quantity represented by the phasor. A phasor that is 90 degrees away from it, means the phasor represents a waveform that is a quarter cycle different from the first waveform.

[@LinhNguyenNhat-ib4su]

Sir, If one current I = -20-j50 , transform this into sine equation, phase angle = arctan(-50/-20)= 68.2 = phase angle in sine equation, right??? Can you explain the way to convert complex numbers to sine equation, Sir? please, I have trouble with phase angle , which angle to be chosen?

[@blahblahblah747]

Great stuff, thank you!

[@BiranchiNarayanNayak]

Nice tutorial..

[@akabir8248]

I appreciate

[@jasonhall947]

Thank you!

[@ugursoydan8187]

why are we using imaginary numbers? shouldn't be the impedance square root(R^2+XL^2)?

[@MichelvanBiezen]

The magnitude yes, but when you want to represent the phase angle, you'll need imaginary numbers.

[@ugursoydan8187]

@@MichelvanBiezen but in other videos,you use this in this form when you are calculating the impedance(with imaginary part). but shouldn't we use it square root(R^2+XL^2) form when we are calculating the total impedance?

[@MichelvanBiezen]

Yes, when calculating the magnitude of the reactance or impedance, but you need the complex representation to show the phase angles between the currents and voltages.

[@ugursoydan8187]

@@MichelvanBiezen ok thanks

[@mab7727]

That Tie is the best thing in this video .. jk, great job! ty

[@MichelvanBiezen]

Thanks! 😄

[@honestman276]

Thanks. From Bangladesh.

[@MichelvanBiezen]

Welcome to the channel!

[@mechanicclemont4799]

Although complex number is an important concept in engineering, the screen quality is too bad :(

[@MichelvanBiezen]

Yes, our older videos are a bit darker. We have added more lighting and used a better camera for our newer videos.

[@ahmedal-ebrashy3691]

What is an imaginary resistance? The concept is strange.

[@carultch]

Imaginary resistance is a contradiction of terms. An impedance can be real or imaginary, or a combination of both, but a resistance is only real. Impedance is an extension of the concept of resistance to the complex number domain, so that it can keep track of both resistances that are real numbers, and the effects of capacitors and inductors that have a reactance rather than a resistance. When impedance is a pure imaginary number, this means that the impedance is entirely reactance, and no resistance. That means that the circuit section in question consists only of components that store energy, and no components that dissipate energy as heat. Reactance means the component stores energy and releases it at a later portion of the cycle.

[@jagatkumartudu]

Sir ,how can I contact u ,any phone contact

[@MichelvanBiezen]

We are very busy, and prefer to communicate via the comments. (always make a new comment instead of keeping a chain going or we may not fint it, since we receive many comments each day).

[@tangoterrier]

Great talk shame it is so dark