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    Courses Electrical Engineering: what study path would be better?

    Hey guys! So basically I'm still finding hard to decide what my specialization field should be next year. I'm really torn between a major in Electronics with a minor in Power Systems with some programming additional courses OR major in Power Systems with minor in Electronics. My favourite...
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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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    Balance of forces: confusion

    1. Homework Statement 2. Homework Equations So I basically have to establish the non linear differential equation that governs the movement of this robot (relates d and theta): 3. The Attempt at a Solution So I know that we should have the sum of torques equal to...
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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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    Confusion about the direction of the vectors: motional EMF

    1. Homework Statement I'm working through an example with motional EMF and I'm having trouble understanding the directions of vectors so that I can apply induction law. The magnetic circuit seems complex because the circuit is used to analyze other situations but the air gap 3, the coil 3 and...
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    Mutual inductance coefficient with so little info

    1. Homework Statement I have the following circuit: The two inductors are connected in series are characterized by internal resistances R1 and R2 and self-inductances L11 and L22. The magnetic coupling factor between the inductors is k = 0.75. The inductors carry the same current i. What...
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    Two voltmeters in parallel measure these different voltages

    1. Homework Statement I'm currently studying induction law and circuits with inductors. I came however with the following circuit: [1]: https://i.stack.imgur.com/ghaiE.png 2. Homework Equations 3. The Attempt at a Solution Now my text says the following: "Unlike what your intuition...
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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

    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

    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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    I 2 definitions for voltage, how are they equivalent?

    So I'm studying electrostatics and I came across to two different definitions of potential difference/voltage (because we're in stationary regimes) and I'm having trouble understanding how the expressions are equivalent. They are for a voltage between point A and point B $$U=V_a - V_b...
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    Studying How to improve in engineering exams

    I don't know if this is the right place to put this, but here it goes... I'm here to ask you what advice can you give me to achieve better results in engineering. I'm currently on my 5th semester and I'm still not managing to get good results. I really put effort on things, prepare myself...
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    Magnetic energy stored in a cylindrical conductor

    1. Homework Statement So I came across with following problem: > Consider a cylindrical conductor of infinite length and circular section of radius a and that is traversed by a stationary current I. What is the magnetic energy stored in the conductor. 2. Homework Equations 3. The Attempt...
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    Energy in a rotating square loop

    1. Homework Statement A square circuit of resistance R=20Ω and side ℓ = 0,2 m spins 100 times per second around an horizontal axis that splits it in two. There is an uniform magnetic field B=1T perpendicular to the position ocupied by the circuit at t=0s. Calculate (1) the magnetic flux, (2)...
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    Magnetic field in the case of a thin magnetized cylinder

    1. Homework Statement Consider a cylinder of thickness a=1 mm and radius R = 1 cm that is uniformly magnetized across z axis being its magnetization M= 10^5 A./m. Calculate the bound currents on the cylinder and, doing convenient approximations, the B field on the axis of the cylinder for z=0...
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    Volume ratio in an adiabatic gas expansion

    1. Homework Statement Consider a perfect monoatomic gas at pressure $p_i$ 1.2 atm and temperature $T_i$ 300K, that is in equilibrium inside a cylinder having a volume $V_i=1L$ and which piston has a mass of 1kg and is at an height of 50 cm. Admit that a mass M=3.13kg is over the piston. When...
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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?

    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?

    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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    Simplify an expression

    1. Homework Statement I have to prove that the expression $$\frac{\omega C - \frac{1}{\omega L}}{\omega C - \frac{1}{\omega L} + \omega L - \frac{1}{\omega C}}$$ is equal to $$\frac{1}{3-( (\frac{\omega_r}{\omega})^2 + (\frac{\omega}{\omega_r})^2)}$$ where ##\omega_r= \frac{1}{\sqrt{LC}}##...
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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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    Bandpass filtering a signal

    1. Homework Statement So let's say that I have a signal of fundamental frequency 50Hz. I then have a band-pass filter that passes the band between 800 and 1000 Hz of my signal. I don't know the expression of the signals I just know the graphics: [![enter image description here][1]][1]...
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    Derivation of the Fourier series of a real signal

    1. Homework Statement Consider the fourier series of a signal given by $$x(t)=\sum_{k=-\infty}^{\infty} a_ke^{jk\omega_0t}$$ Let's consider an approaches to this series given by the truncated series. $$x_N(t)=\sum_{k=-N}^{N} a_ke^{jk\omega_0t}$$ a- Show that if $x(t)$ is real then the...
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    Coaxial cable conductors with dielectric: polarization of charge

    1. Homework Statement Consider a coaxial cable which consists of an inner cylindrical conductor of radius R1, and a shell cylindrical conductor of radii R2 and R3. The 2 conductors are separated with a dielectric material of permittivity ε. Consider the length of the cable, ℓ, much larger than...
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    Total charge dielectric

    1. Homework Statement Consider an infinite environment with electrical permittivity non-homogeneous $$\epsilon=\epsilon_0(1+a/r)$$ a being a positive constant. A conducting sphere of radius R and charge Q is put on that environment, centered at r=0. Determine the electric field $$E$$, the...
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    Electric field in a capacitor with a dielectric

    1. Homework Statement A parallel plate capacitor has 2 square plates of side l, separated by a distance d (l is a lot bigger than d). Between the plates, there is a linear and non-homogeneous dielectric with constant $$\epsilon_R=1+ay$$ with $$a$$a positive constant. Calculate the electric...
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    Spherical conductor shell problem

    1. Homework Statement Consider a spherical conducting shell with inner radius R2 and outer radius R3, that has other spherical conductor inside it with radius R1 (this one is solid). Initially the 2 spheres are connected by a wire. We put a positive charge Q on the sphere and after some time we...
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