# Use of complex numbers in electrical engineering. Complex numbers (video) 2019-01-22

Use of complex numbers in electrical engineering Rating: 5,6/10 1169 reviews

## What is the application of complex analysis in engineering? Vector Rotation of the j-operator So by multiplying an imaginary number by j 2 will rotate the vector by 180 o anticlockwise, multiplying by j 3 rotates it 270 o and by j 4 rotates it 360 o or back to its original position. To convert from cartesian to polar form: To convert from polar to cartesian form: Complex conjugates The conjugate of a complex number is a complex number with the same magnitude but inverse angle or equivalently inverse imaginary part. For this reason, all further discussion below assumes that phasors represent r. I don't hang my understanding of a subject on an instructor, so I have gathered a couple of references dedicated to explain complex analysis, and I'm ready to go. Perhaps it affects, but its not yet proven or observed.

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## capacitor Followup question by Greg Castle, Dickson College Australia on October 21, 1996: I am doing an assignment on complex numbers and their applications in the real world. Its the rule of Complex numbers. C99 for instance has complex. The question: is nice but covers a more mathematical perspective on interim results that make solving a problem easier. That's what we call a , and that little guy is the strongest weapon you have against tough circuits. Many forms of power are basically the square of some excitation measure.

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## capacitor Then the addition of a complex number and its conjugate gives the result as a real number or active component only, while their subtraction gives an imaginary number or reactive component only. The symbols i, j, and k are used for unit vectors in the directions of the x, y, and z axes respectively. What's a little bit lacking in these examples so far is why it is complex numbers rather than just two-dimensional vectors that are appropriate; i. And, you will be successful in counting so with accurate results. Now just apply this concept to the Complex number. The impedance of a resistor is just equal to its resistance: Inductors are purely reactive. It is true that in most cases no one needs to perform rigorous complex analysis for every new problem they solve.

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## Why use j for imaginary unit? Anything that leans hardware or scientific really. I'd like to add a related point here. Provide details and share your research! It makes for a nice demonstration in a classroom. We have also seen that Complex Numbers can be presented in rectangular, polar or exponential form with the conversion between each complex number algebra form including addition, subtracting, multiplication and division. You might have seen the above written in a slightly different form before, but the general idea is to take a function written in one variable and write it in terms of another. Hence no need to keep track of whether you're using sine or cosine. You might have seen that we never disturb or calculate an imaginary part with a real part.

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## Complex Numbers and Phasors in Polar or Rectangular Form I have found some fields where they are used, in engineering for example, but I really require formulas. It is not only analysis where we need to manipulate information but also the design of circuits. The following is a personal opinion, but I think mathematics, no matter how rarefied and strange, is a kind of reflection of the world. Ok but what has an imaginary vector in common with a voltage? The virtual Forum provides free access 25 on-demand webinars which have been recorded at electronica. Why that shouldn't apply to linear filter design I can't see. So if you're gonna do this on your calculator you would say that theta equals the inverse tangent of y over x.

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## Complex numbers (video) Hankel functions then are complex just the mathematical meaning linear combinations of Bessel functions of the first and second kinds. The compiler can optimize in ways not possible with a library. Now lets enter into the second one, its practical use. Since we're speaking of sines and cosines all at the same frequency it's only a matter of phase shift following proper sign convention. In principle, any voltage or current phasor in the network can be chosen as the reference. The points on the Argand diagram for a complex conjugate have the same horizontal position on the real axis as the original complex number, but opposite vertical positions.

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## Question Corner The power factor is the cosine of , the phase difference between current and voltage in the circuit. I hope the formulas in this and the previous example are of some use to you. Therefore, passing through complex numbers gives a direct method of solving a differential equation, even though the equation itself and the final solution are all real-valued. Tl;dr learn them, but don't worry about them. Then the relationship between, Exponential, Polar and Rectangular form in defining a complex number is given as. Are complex numbers used in programming? Well let me tell you two things. In this case the points are plotted directly onto the real or imaginary axis.

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## circuit analysis A vector has an amplitude, that is its length, and a phase, that is the angle it forms with the x axis, ccw direction is positive. Programming for business, web apps, smartphones, and games rarely has any use for complex numbers. I have yet to take any course related to communications, not even Electromagnetic waves, so here I come to ask, how much do I really need to know about complex analysis to be able to perform very good in communication courses, and to be able to design communication systems? I just want to ask about the importance of Complex numbers analysis in the discipline of Electronics and Communications Engineering. It turns out that algebra using sines and cosines is tenuous. And would it be recommended to learn how to implement them for a programming job if so please specify what job? It has a real part resistance R and an imaginary part reactance X : where the reactance X is generally a function of frequency. Any recommended books on complex analysis for electrical engineers? For that matter why should the mechanical engineer who analyses vibrations not count it a real world application when it makes him able to predict in advance the effects of the vibration of his system on a structure? The operators Re and Im are used to select the real and imaginary parts of a complex value.

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## Careers That Use Complex Numbers And check other more concise answer too. It is just a helpful mathematical tool. Fourier transforms use complex numbers and are the key to working with wavefunctions, designing filters, signal integrity in digital electronics, radio astronomy, and on and on. Well try to imagine the Gauss plane, the x axis is the real axis, the y axis is the imaginary one. The real and imaginary parts of a complex number are abbreviated as Re z and Im z , respectively. This linkage is critical to Euler's Identity: You'd cover complex numbers in a huge variety of courses ranging from Electrical Engineering to Numerical Analysis. In each successive rotation, the magnitude of the vector always remains the same.

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