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    Engineering Parameters of transformers: open and short-circuit tests

    I expected to get 27,6 mH By doing what you guys said I get to a turns ratio of 2 (dividing the voltages voltages). That means the current I2rms is 2 times current I1rms equals to 10V. That means L22 = LM/2 = 15.9 mH
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    Engineering Parameters of transformers: open and short-circuit tests

    Thanks for your contribution but that is wrong :/ It makes me obtain a wrong value for L22
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    Engineering Parameters of transformers: open and short-circuit tests

    1. Homework Statement Ok I have the following circuit and data (when the subscript is "ef" it means "rms" values): I am asked to determine the parameters of the transformer r1 L11, L22 and LM with the given experimental data. 2. Homework Equations 3. The Attempt at a Solution I had...
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    Dot convention inductors in series: equation confusion

    1. Homework Statement So I'm really confused with mutual inductors and dot convention. If your answer is going to be a link to any website I can assure you I read them all and that only left me more confused. So here are my questions: 2. Homework Equations 3. The Attempt at a Solution ->...
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    Modeling a third order system

    1. Homework Statement Determine the parameters of the PI controller such that two of the closed-loop poles of the transfer function Gclr(s) correspond to the poles of a second order LTI system with the following specifications: i) overshoot S% = 25%; and ii) settling time ts(5%) = 120 s. 2...
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    Transmission line: leakage current differential equation

    Really can't anyone help me? I've been around this problem for an entire day I'm losing my mind with this, it must be a simple math trick I have no freaking idea about...
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    Transmission line: leakage current differential equation

    1. Homework Statement I have a coaxial cable with internal conductor of radius r1 and external conductor of radii r2 and r3. The material of the conductors has a conductivity ##\sigma_1##. Between the conductors there is a imperfect dielectric of conductivity ##\sigma_2##. Consider the...
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    System of multiple conductors: image method

    1. Homework Statement The following figure represent the traversal cut of a system with two cylindrical equal conductors of radius r0 length l at a distance d from one another and at the same distance h of a plane conductor (conductor zero). The dielectric that surrounds the conductors is the...
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    Partial capacitances of a system of conductors

    Hey berkeman! Thank you for trying to help. Yes partial capacitances are a little bit different than "regular capacitances" (i.e. the capacitances that figure out on a capacitance matrix). What my book says is " An alternative method – the so-called partial capacitance scheme – consists of...
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    Partial capacitances of a system of conductors

    1. Homework Statement I have a small question about the following problem. The figure represents the cross-section of a three-conductor system comprising a communications coaxial cable of length l running parallel to a conducting wall (reference conductor). Determine the partial capacitance...
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    Magnetic field of a ferromagnetic cylinder

    Ok, got it! This was a very interesting problem indeed, so thank you for your recommendation.
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    Magnetic field of a ferromagnetic cylinder

    @Charles Link as you advised me I gave a look into this problem. I have a few questions though that I hope you can help me clarify. My doubts are in the expression you use (the constant ##\mu_0##). Shouldn't we use ? And ? However by doing that I get to ##B= \mu_0 M##. Is that wrong?
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    Engineering Determine the input impedances of a circuit

    Hi! Yes I considered the theoretical model given in class, that takes beta as a constant. I also noticed that the LTSPICE model of the transistor includes a finite value for the Early voltage, while in the theoretical analysis we are instructed to assume that this voltage is infinite (therefore...
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    Engineering Determine the input impedances of a circuit

    Do you have any idea what's going wrong?
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    Engineering Determine the input impedances of a circuit

    The fact that I obtained 240K in my theoretical analysis... It's an error of 17%, isn't this too much? I'm afraid 240k is the wrong value, but I revised my calculations and I don't see the mistake.
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    Engineering Determine the input impedances of a circuit

    Ri2 is the INPUT impedance of the second step of amplification. Yes, RL charges the output of the circuit
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    Engineering Determine the input impedances of a circuit

    Hi! I did a new measure considering the peak of the output voltage as the frequency to measure my resistances and obtained 19.6 k for Ri1 (which is pretty satisfactory)... But 200 kohm for Ri2! What am I doing wrong?
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    Engineering Determine the input impedances of a circuit

    1. Homework Statement I'm studying a circuit with BJT's and I'm asked to determine the input resistances of the two amplification steps of the circuit. The circuit I'm analyzing is the following one: 2. Homework Equations 3. The Attempt at a Solution To determine the input resistances I...
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    Engineering Biasing circuit with a MOSFET: am I missing something

    1. Homework Statement I have the following circuit with MOSFET (cascode amplifier). [![enter image description here][1]][1] [1]: https://i.stack.imgur.com/BAqQh.png Information given: ##V_t=1V## ##I_1=20\mu A## ##k=10 \mu AV^{-2}## Knowing that ##V_b## is 5V determine the minimum value...
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    Mosfet equation: how to get it?

    Oh I got what I was doing wrong! I was assuming the current I_D was constant when taking the derivative which is obviously wrong. Thanks!
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    Mosfet equation: how to get it?

    What do you mean? Why using the chain rule here? I'm supposed to take the derivative of I_D in relation to V_t and that's exactly what I'm taking.
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    Mosfet equation: how to get it?

    I get $$-2k(V_G - R_SI_D-V_t)$$
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    Mosfet equation: how to get it?

    1. Homework Statement I'm studying the following circuit with a MOSFET [![enter image description here][1]][1] [1]: https://i.stack.imgur.com/gEEdQ.png 2. Homework Equations 3. The Attempt at a Solution Now for analyzing this circuit my book came out with various equations (which I...
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    What does this voltmeter measure?

    Hi! Oh yes that's the better approach, I didn't thought about it, thanks! The phase difference between the voltages across the inductor and the capacitor is \pi. Since the overall effective voltage is 1 that leaves us with two options: the voltage on the capacitor is zero (this is the case...
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    What does this voltmeter measure?

    1. Homework Statement Consider the following circuit where i(t) is sinusoidal and exists across both components. (1) is an inductor and (2) is a capacitor. The ideal voltmeters measure effective value. What is the value measured by V2: [![enter image description here][1]][1] [1]...
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    Engineering Analysis of a servo motor

    1. Homework Statement 2. Homework Equations I'm studying a mathematical behaviour of a servo motor and I need some help to understand it. The output signal is \$\beta (t)\$, representing the angle rotated by the axis at instant t, in relation to the equilibrium position. On the servomotor...
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    KCL with phasors: how to proceed knowing effective values

    1. Homework Statement I have the following problem. Consider a circuit node where 3 sinusoidal currents with the same frequency converge, i1 i2 and i3. Knowing that the effective values of i1 and i2 are I1ef=1A and I2ef=2A. What can we say about I3ef: Options: $$(a)1A \leq I_{3ef} \leq 3A$$...
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    3 resistors in parallel: how to get there

    Oh I finally got it! Thank you very much !!
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