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5 votes
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Why does the reciprocal of sum of reciprocals relationship appear commonly?

Resistance isn't the only descriptor of the behaviour of a resistor. That same behaviour could be represented by the reciprocal of resistance, which is conductance (usually called \$G\$): $$ G = \frac{...
Simon Fitch's user avatar
4 votes
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How is the reactance of a capacitor formulated?

The math Consider this linear differential equation with real coefficients $$\frac{\text{d}\ y(t)}{\text{d}t} + a_0y(t) = b_0x(t) \tag1$$ Assume now that the input and output are complex valued ...
Carl's user avatar
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3 votes
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Is a capacitor a memoryless system?

then the current only depends on the derivative of voltage at that particular instant of time only, You are just trying to shift the memory to the voltage input, rather than the capacitor state. The ...
Neil_UK's user avatar
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3 votes
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Why does tan (θ) equals -j in impedance of reactive circuits?

The error is a matter of definition: When you divide instantaneous voltage by current, you get an impedance, but you don't get the impedance as used in conventional terms. Note that such a definition ...
Tim Williams's user avatar
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3 votes
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10 µF and 0.1 µF capacitors not making any difference in filtering out noise

Decoupling capacitors are important. And they are a cargo cult. We put them in in the hopes that they prevent us from having problems. And they can do the job. You'll just never know if you needed all ...
kruemi's user avatar
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2 votes

How is the reactance of a capacitor formulated?

How exactly does the reactance formula Xc=1ωC come about? \$\mathbb{V}=V_0\exp\left(j\,\omega t\right)\$. (Note: The vector length is unchanging. It's tip forms a helix traveling in time. A voltage ...
periblepsis's user avatar
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2 votes
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If ESR for a capacitor is not given, can you use f, C, and Q to calculate it?

Yes, these are correct definitions, in as much as is shown/used. Keep in mind the complete definition of ESR: it's effective because it varies with frequency. DF is normally measured at low ...
Tim Williams's user avatar
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2 votes
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Energy stored in a capacitor with dielectric

If the dielectric was not there, the capacitance would the same as if \$ε_r\$ =1. So the difference is stored in the dielectric.
Spehro Pefhany's user avatar
2 votes

Why does tan (θ) equals -j in impedance of reactive circuits?

The equality $$ \text{tan}(\omega t)=-j $$ doesn’t hold. The tangent is a real quantity while \$-j\$ is an imaginary quantity. Recognize that the sine is associated with one signal and the cosine with ...
RussellH's user avatar
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2 votes

What are the functions of these capacitors connected to the output of a efuse?

C5-C6 as well. Or, you could equally well ask: why are C3 and C4 equal here? The topic is PDN (power distribution network) analysis, and I won't go into detail here (as hard as that may be to believe,...
Tim Williams's user avatar
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1 vote
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Inductor and capacitor in parallel should not yield resultant current in phase w/ voltage

"Inductive load" here means a load with an overall inductive component to its current in addition to any in-phase current, not a purely inductive load. I.e. a phase angle between 0 and +90. ...
vir's user avatar
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1 vote

Why does the reciprocal of sum of reciprocals relationship appear commonly?

It simply means that the unit you're using for this measurement is the reciprocal of the quantity that you're actually adding. When you put two resistors in series, you're literally adding more ...
hobbs's user avatar
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1 vote

Why does the reciprocal of sum of reciprocals relationship appear commonly?

It appears in many contexts, as it's the sum of the harmonic mean of the elements, one of the ways of finding the "most normal value" of a set of values. Typically it's used for rates, such ...
jonathanjo's user avatar
1 vote

How is the reactance of a capacitor formulated?

In an ideal capacitor, there are no parasitic resistances so the real component to the impedance is just zero and the phase angle is -90 degrees or -j. It can also be written as Z = 0 - jωC. In real ...
vir's user avatar
  • 20.3k
1 vote

What are the functions of these capacitors connected to the output of a efuse?

The boost converter TPS61085 has Cout recommendations. 2x10uF is recommended as usually working well. The loop response is dependent on Cout as well as feedback components, but those relationships ...
JkingNH's user avatar
  • 154

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