Recent content by eyeweyew

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    Confusion about applying Faraday's law to a circuit

    Yes, you are right. The correct equation for loop1 should be: $$\oint_C {E \cdot d\ell} = -V+I_tR_t+I_1R_1=-\frac{d\Phi_{B}}{{dt}}=0$$
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    Required force for sphere start rolling

    Assume there are two objects on the same surface, one is a cube and the other is a sphere. Both objects have the same mass m. The required applied force to the center of mass of the cube for it to start sliding should be equal to static friction force: μs⋅m⋅g. But what is the required applied...
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    I Does path independence still hold if permittivity is non-uniform?

    I look into the example 1 in this reference and I find something that bothers me a little bit. When I try to find potential and electric field at the point 2d distance away from the q charge in both dialectrics ε1 and ε2 on the z-axis(s=0), i.e.: p1 and p2 in the following picture. I got for p1...
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    Confusion about applying Faraday's law to a circuit

    If all electric fields generated by electrostatic charges, then we know $$\oint_C {E \cdot d\ell} = 0$$ so in the following circuit, $$\oint_C {E \cdot d\ell} = -V+IR = 0$$ In cases where not all electric fields generated by electrostatic charges, then according Faraday's law, we know...
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    I Does path independence still hold if permittivity is non-uniform?

    I want to confirm I understand path independence correctly in circuit analysis. In the circuit below, since for loop1, we have $$\oint_{closed}^{}\overrightarrow{E}\cdot{d}\overrightarrow{l}=-V+I_tR_t+I_1R_1=0$$ and for loop2 we have...
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    I Does path independence still hold if permittivity is non-uniform?

    Thank you so much for all the answers here! Just one last thing, I want to confirm other than this particular case, it is true that path independence holds if permittivity is non-uniform in general right? Thanks!
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    I Does path independence still hold if permittivity is non-uniform?

    Thanks for posting this reference!
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    Engineering Bending of vacuum level in pn junction

    When both isolated p-type and n-type materials join together and form pn-junction as picture attached, the vacuum energy level also bend so it is higher on the the p-side than on the n-side. Does that mean the absolute energy of an electron that is just outside the material on the p-side higher...
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    I Does path independence still hold if permittivity is non-uniform?

    Consider a scenario in the picture where one half of space consists of a material with permittivity ϵ1 and the other half consists of a material with permittivity ϵ2, where ϵ1 > ϵ2. A unit positive charge is fixed at the interface between the two materials. Path1 is entirely within the material...
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    I Electric Potential in circuit

    It is voltage at a point due to other point charges. I edited my post to clarify it. Thanks!
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    I Electric Potential in circuit

    I reviewed some of the fundamental physics and I looked back at the equation for Electric potential at a point p: $$V(p) = k \sum_{i} {\frac {q_i} {r_i}}$$ where - p is the point at which the potential is evaluated; - ri is the distance between point p and point i at which there is a nonzero...
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    Engineering Unable to model Transresistance amplifier with feedback correctly

    I think I got it. I mixed up the current i1 going into the input port with the current source i
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    Engineering Unable to model Transresistance amplifier with feedback correctly

    I spent the whole day trying to figure why transresistance amplifier modelled with z-parameters does not match with nodal analysis results but I sill can't figure out. I desperate need help on this... I write down step by step what I did for a very simple transresistance amplifier here and hope...
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    Engineering H-parameter model for non-inverting amplifier

    The final feedback would be fvo where f=RE/(RE+Rf) so it is from right to left.
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    Engineering H-parameter model for non-inverting amplifier

    Nevermind, the results matched when I include h21.
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