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1. Engineering Parameters of transformers: open and short-circuit tests

@gneill can you help me? please?
2. 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
3. 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
4. Engineering Parameters of transformers: open and short-circuit tests

Can someone help me please? :(
5. 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...
6. 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 ->...
7. 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...
8. 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...
9. 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...
10. 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...
11. 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...
12. 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...
13. Magnetic field of a ferromagnetic cylinder

Ok, got it! This was a very interesting problem indeed, so thank you for your recommendation.
14. 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?
15. 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...
16. Engineering Determine the input impedances of a circuit

Do you have any idea what's going wrong?
17. 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.
18. 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
19. 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?
20. 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...
21. 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]] : 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...
22. 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!
23. 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.
24. Mosfet equation: how to get it?

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

1. Homework Statement I'm studying the following circuit with a MOSFET [![enter image description here]] : 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...
26. 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...
27. 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]] ...
28. 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...
29. 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: $$(a)1A \leq I_{3ef} \leq 3A$$...
30. 3 resistors in parallel: how to get there

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