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Questions tagged [electrical-resistance]

The tag applies to electrical resistance and resistors. DO NOT USE THIS TAG for non-electrical resistance.

The tag applies to electrical resistance. It also applies to e.g. resistors, electrical resistivity and conductivity, and electrical impedance. DO NOT USE THIS TAG for non-electrical resistance, such as, e.g., air resistance.

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On this infinite grid of resistors, what's the equivalent resistance?

I searched and couldn't find it on the site, so here it is (quoted to the letter): On this infinite grid of ideal one-ohm resistors, what's the equivalent resistance between the two marked nodes? With a link to the source. I'm not really sure if…
Malabarba
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Why doesn't current pass through a resistance if there is another path without resistance?

Why doesn't current pass through a resistance if there is another path without resistance? How does it know there is resistance on that path? Some clarification: I understand that some current will flow through the resistance. A depiction of this…
ten1o
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Why do we use AC for long distance transmission?

Why do we use AC (Alternating Current) for long distance transmission of electrical power? I know that AC is such a current that changes polarity (magnitude and direction) and has fixed poles.
EiNsTeIn
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What *exactly* is electrical current, voltage, and resistance?

I am taking AP Physics right now (I'm a high school student) and we are learning about circuits, current, resistance, voltage, Ohm's Law, etc. I am looking for exact definitions of what current, voltage, and resistance are. My teacher, as I'm sure…
Addison
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I don't understand what we really mean by voltage drop

This post is my best effort to seek assistance on a topic which is quite vague to me, so that I am struggling to formulate my questions. I hope that someone will be able to figure out what it is I'm trying to articulate. If we have a circuit with a…
oyvey
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Will the volt, ampere, ohm or other electrical units change on May 20th, 2019?

When watching a video by Veritasium about the SI units redefinition (5:29), a claim that the volt and unit of resistance (presumably the ohm) will change by about 1 part in 10 million caught my attention: [...] I should point out that a volt will…
user231851
39
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If the Earth is a good conductor of electricity, why don't people get electrocuted every time they touch the Earth?

Since the Earth is a good conductor of electricity, is it safe to assume that any charge that flows down to the Earth must be redistributed into the Earth in and along all directions? Does this also mean that if I release a million amperes of…
Swami
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How can Ohm's law be correct if superconductors have 0 resistivity?

Ohm's law states that the relationship between current ( I ) voltage ( V ) and resistance ( R ) is $$I = \frac{V}{R}$$ However superconductors cause the resistance of a material to go to zero, and as I understand it, as $R \to 0$, $I \to \infty$.…
Loourr
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Reversed First Joule's Law : heating a resistor produce voltage?

I was discussing about the theory that claims that "every emitter also behaves like a receptor": Are emitters always receptors? I was brilliantly told that this theory would be false for fluorescent lights and also for resistors, because of entropy…
Technico.top
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Electricity takes the path of least resistance?

Electricity takes the path of least resistance! Is this statement correct? If so, why is it the case? If there are two paths available, and one, for example, has a resistor, why would the current run through the other path only, and not both?
Paul Michaels
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Is there a simple proof that Kirchhoff's circuit laws always provide an exactly complete set of equations?

Suppose I have a complicated electric circuit which is composed exclusively of resistors and voltage and current sources, wired up together in a complicated way. The standard way to solve the circuit (by which I mean finding the voltage across, and…
Emilio Pisanty
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Could someone intuitively explain to me Ohm's law?

Could someone intuitively explain to me Ohm's law? I understand what voltage is and how it is the electric potential energy and that it is the integral of the electric field strength etc. I also understand that current is the rate at which charge…
user3333708
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Resistance between any 2 nodes on an infinite square grid

This question is motivated by this xkcd comic strip . The problem is indeed interesting, and my first recollection upon reading this was a similar problem in the book Problems in General Physics by I.E.Irodov(which, in my humble opinion,is a…
Koundinya Vajjha
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Why does vacuum have a nonzero characteristic impedance towards electromagnetic radiation?

On Wikipedia, the impedance of free space $Z_0$ is defined as square root of the ratio of the permeability of free space $\mu_0$ to the permittivity of free space $\epsilon_0$, i.e. $$Z_0 = \sqrt{\mu_0 / \epsilon_0} \, .$$ The value is approximately…
quantum231
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What's the physical meaning of the imaginary component of impedance?

As you know, impedance is defined as a complex number. Ideal capacitors: $$ \frac {1} {j \omega C} \hspace{0.5 pc} \mathrm{or} \hspace{0.5 pc} \frac {1} {sC} $$ Ideal inductors: $$ j \omega L \hspace{0.5 pc} \mathrm{or} \hspace{0.5 pc} sL $$ I know…
Venemo
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