Questions tagged [electric-circuits]
An electronic system, with closed loop current flow, and relative electrical potentials present across electrical components.
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On this infinite grid of resistors, what's the equivalent resistance? [closed]
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?
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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 ...
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In what order would light bulbs in series light up when you close a long circuit?
For a few days, I was thinking of this question.
Lets assume we have a simple circuit that is 100 meters long. And lets say that we have bulbs A, B and C connected to the circuit's 30th, 60th and ...
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Intuitively, why does putting capacitors in series decrease the equivalent capacitance?
Can someone please explain, intuitively (without any formula, I understand the formulas), why the equivalent capacitance of capacitors in series is less than the any individual capacitor's capacitance?...
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Cyclist's electrical tingling under power lines
It's been happening to me for years. I finally decided to ask users who are better with "practical physics" when I was told that my experience – that I am going to describe momentarily – prove that I ...
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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, ...
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Why do we use Root Mean Square (RMS) values when talking about AC voltage
What makes it a good idea to use RMS rather than peak values of current and voltage when we talk about or compute with AC signals.
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Difference between live and neutral wires
In domestic electrical circuits, there are 3 wires - live, earth and neutral. What is the difference between the live and neutral wires?
As there is AC supply, it means that there are no fixed ...
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Does alternating current (AC) require a complete circuit?
This popular question about "whether an AC circuit with one end grounded to Earth and the other end grounded to Mars would work (ignoring resistance/inductance of the wire)" was recently asked on the ...
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Birds on a wire (again) - how is it that birds feel no current? They are just making a parallel circuit, no?
I have been thinking about this and I know that other people have answered this on here, but there's one part that still baffles me, and it has to do with parallel circuits.
If I connect a battery ...
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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 ...
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If electrons are identical and indistinguishable, how can we say current is the movement of electrons?
When we talk about current, we say electrons are "flowing" through a conductor. But if electrons are identical particles, how does it make sense to talk about them flowing?
To expand on that:...
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When jumping a car battery, why is it better to connect the red/positive cable first?
When jumping a car battery the standard advice is to connect the red (positive) cable first. What's the physics explanation for this?
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What happens to an inductor if the stored energy does not find a path to discharge?
Suppose an inductor is connected to a source and then the source is disconnected. The inductor will have energy stored in the form of magnetic field. But there is no way/path to ground to discharge ...
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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 ...
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How does energy flow in a circuit? Which is correct?
I have been very interested in this question since reading Electricity Misconceptions by K-6
There are two perspectives I have come across for how energy flows in a circuit:
Electrons carry charge. ...
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What is the most appropriate mathematical theory for electrical circuits?
What exactly are electrical circuits as mathematical objects?
It seems quite intuitive to me, that they are geometric realization of some graph with some additional structure.
Another thing I notice ...
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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 ...
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Is every open circuit a capacitor?
I think that even open-ended wires can let AC current flow through them, just with a low capacitance. I also think an antenna could be a capacitor and open ended. Am I thinking correctly?
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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 ...
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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 (...
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Why is there an electric field in a wire even though it is a conductor?
If you take a perfect conductor, there cannot be a field across it since if there were, the particles would arrange themselves in a way to cancel out the field right?
Yet, why does the same not hold ...
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Why don't superconductors, which have zero electrical resistance, violate the second law of thermodynamics?
There are bunch of questions on here asking whether superconductors really have exactly zero resistance and answers saying they do. My question is how this doesn't violate the second law of ...
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How does power consumption vary with the processor frequency in a typical computer? [closed]
I am looking for an estimate on the relationship between the rate of increase of power usage as the frequency of the processor is increased.
Any references to findings on this would be helpful.
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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....
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Are voltages discrete when we zoom in enough?
Voltages are often thought of as continuous physical quantities.
I was wondering whether by zooming in a lot, they are discrete.
I feel like the answer to the above question is yes as voltages in the ...
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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 \...
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Why is capacitance defined as charge divided by voltage?
I understand that capacitance is the ability of a body to store an electrical charge and the formula is $C=\frac{Q}{V}$. What I don't understand, however, is why it is defined as coulomb per volt. Of ...
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What happens to half of the energy in a circuit with a capacitor?
For a simple circuit with a battery supplying a voltage $V$ to a capacitor, let us assume that the charge on the capacitor is $Q$. Now, the work done by the battery or the energy supplied is given by ...
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What happens when we connect a metal wire between the 2 poles of a battery?
As I remembered, at the 2 poles of a battery, positive or negative electric charges are gathered. So there'll be electric field existing inside the battery. This filed is neutralized by the chemical ...
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