Questions tagged [electric-circuits]
An electronic system, with closed loop current flow, and relative electrical potentials present across electrical components.
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Why does a capacitor act as a frequency filter?
What is it about a capacitor which allows it to filter frequencies?
I understand the construction of a high-pass RC filter, and the mathematics behind it, but I'm struggling to find an explanation of ...
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Understanding voltage and power in the fluid analogy for DC circuits
I am trying to understand electric circuits (ie voltage, current, power, and resistance). For the most part, everything makes perfect sense, but for some reason I do not feel as if I understand the ...
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What's the reason behind the current remaining the same after passing by a resistance?
I've been wondering why does this really happen, I mean by intuition if electrons are driven by EMF (ignoring wire's resistance), $n$ coulombs would pass by a point per second, until they encounter ...
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Why is there an electric field around this closed electric circuit?
I have difficulty understanding the picture below. I can understand the green magnetic fields. But why is there an outside, red, electric field? Isn't the electric field guided entirely through the ...
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Symmetry in resistor circuits
Given 6 points that are connected with each other with a resistor of
resistance $R$, find the resistance between any two points. (Answer: $R/3$)
(All the conducting wires have the same resistance $...
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Why do two connected 1.5-volt batteries become a 3- volt battery?
Why two connected 1.5 volt battery become 3 volts?
If one battery plus side is connect to minus side of another battery, there should be a current flow between them until no free charge move anymore, ...
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Kirchhoff's Voltage Law in a General Electromagnetic Field
Recently, Prof. Walter Lewin and YouTuber ElectroBOOM started a discussion about KVL, after Dr. Lewin claimed that KVL did not hold in the presence of an magneto-dynamic field. I would argue that Dr. ...
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Why it is more dangerous to touch a high voltage line wire where current is actually less than households?
I have seen that power is transmitted from power stations to households at high voltage and low current to minimize the power loss.
That means the current in the transmission line is less than the ...
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What are the different methods for a resistor circuit that isn't parallel or series? [closed]
What are the different approaches to determine the equivalent resistance of nontrivial resistor networks in general, that cannot be reduced by the usual series and parallel rules? (The diagram below ...
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How does current flow in a circuit with a capacitor?
When a capacitor is connected to a battery, current starts flowing in a circuit which charges the capacitor until the voltage between plates becomes equal to the voltage of the battery.
Since between ...
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Is every finite circuit "solvable" using Ohm's law and Kirchhoff's loop rules? [duplicate]
Whenever I have solved circuits (only cells, resistors and wires), it has only been necessary to use Ohm's law (or things derived from Ohm's law, such as how two resistors $R_1$ and $R_2$ have ...
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How can KVL & KCL be derived from Maxwell equations?
How can KVL (Kirchhoff's Voltage Law) & KCL (Kirchhoff's Current law) be derived from Maxwell equations in lumped circuits? (Lumped network: if $d$ is the largest dimension of the network and $\...
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Derivation of Ohm's Law
Is it possible to derive Ohm's law (perhaps in some appropriate limit) from Maxwell's Equations?
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What happens if I throw a battery into water?
Today I have by accident thrown a AAA battery into a bucket of water. I fished it out of the water immediately (within 20 seconds or so) and nothing notable had happened and the battery is still full ...
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How does my hand amplify an FM radio signal?
I have a gizmo that broadcasts an FM radio signal from my phone's headphone socket to my car's radio antenna.
Sometimes, there's another station on the same frequency with a stronger signal and my ...
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