# Tag Info

### Why doesn't current pass through a resistance if there is another path without resistance?

The basic circuit theory "rules" you imply, are high level simplifications applicable at a large scale and at slow speeds. If you look at it close and fast enough, you could say that a current really ...
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### If water is not a good conductor, why are we advised to avoid water near electricity (no wet hands near circuits etc.)?

"Pure" water is a very poor conductor (resistivity is actually used as a measure of purity). "Real" water is not pure - it contains electrolytes and is quite conductive. Also - ...
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Accepted

### Why doesn't Kirchhoff's Law work when a battery is shorted with an ideal wire?

Just to complement the other answers: This isn't really about Kirchhoff's law. Rather, it is about an idealised situation that does not have a solution at all. When you draw such a diagram, you can ...
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### Why doesn't current pass through a resistance if there is another path without resistance?

I'll try to offer a simpler analogy of how that works. Camp A on the side of a mountain is full of hikers. There is another empty campsite B on the other side of the mountain. And there are two ...
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### Calculating equivalent resistance

I am used to smoothing out badly shaped circuits by pulling the wires: Then I get a better circuit by cutting the extra wires: So there are three resistors in parallel, indicating that the current ...
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### If water is not a good conductor, why are we advised to avoid water near electricity (no wet hands near circuits etc.)?

The problem is in the definition what a "good" or "bad" conductor is. In school children are taught that everything is quite easy: there are "good" conductors like metals ...
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### Why doesn't current pass through a resistance if there is another path without resistance?

If there is a parallel path without resistance then the voltage across the terminals is zero. If the voltage is zero then, by Ohm’s law, the current through any branch with resistance is also zero.
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### Why doesn't Kirchhoff's Law work when a battery is shorted with an ideal wire?

The law does hold up perfectly here. There's a battery, with v volts. Let's use 5v. Then, there's a wire. In the circuit above, there will be some (high) current ...
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### If water is not a good conductor, why are we advised to avoid water near electricity (no wet hands near circuits etc.)?

In high school my chemistry teacher, Mr Stratton, set up an experiment. He had a light bulb fixture on a wooden paddle, with a power cord attached and two metal prongs projecting at right angles, ...
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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? Stipulate that there are two parallel connected resistors with resistance $R_1$ and $R_2$ respectively. ...
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### Why doesn't Kirchhoff's Law work when a battery is shorted with an ideal wire?

Kirchoff's law only applies to consistent circuits. It is possible to write a circuit which is not self-consistent using ideal wires and ideal batteries, but any tool which gives you a solution for ...
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### If water is not a good conductor, why are we advised to avoid water near electricity (no wet hands near circuits etc.)?

Water is indeed NOT a good conductor UNLESS impurities exist. And if you could keep the impurities from contaminating it, you could put a radio in it and it would still work. You can find out yourself....

### Why doesn't current pass through a resistance if there is another path without resistance?

Current will flow through all possible paths no matter how high the resistance. The amount of current flowing through any given path will depend upon voltage and resistance. Given two parallel paths, ...
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### Will current pass without any resistance?

Okay, there are a lot of interesting questions packed in here; I can definitely see why @rpfphysics put a bounty on this one! Are resistors necessary in a circuit? This answer is an emphatic no. ...
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### Why doesn't current pass through a resistance if there is another path without resistance?

Greatly simplified, let's say we have some electrons and two paths: Now we apply electric field to them and they move: The ones in the low resistance path have moved quite a distance, but the ones ...
Accepted

### Why does the LED turn off if the high current is going through the short?

If I'm reading your post right, I don't think you're asking the question you mean to ask. You understand that 0 resistance is not needed for a short, all that is needed is very low resistance so the ...
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### Why doesn't Kirchhoff's Law work when a battery is shorted with an ideal wire?

There are a number of points here. First if you are saying that there is no resistance in the circuit and nothing else is present then the situation is unphysical and as such you cannot apply ...
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### Why does a short circuit occur?

A "short circuit" generically just refers to electricity taking a more optimal path than you may have desired it take. That is, there is an accidental bridge in the circuit such that ...
• 1,785
Accepted

Yes. The equivalent resistance for $n$ equal resistors of value $R$ connected in parallel is $R(n)=\frac{R}{n}$. As $n \to \infty$ then $R(n) \to 0$, provided that $R$ is finite.
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### If water is not a good conductor, why are we advised to avoid water near electricity (no wet hands near circuits etc.)?

Water is a poor conductor compared to wires and metal, but is an excellent conductor compared to air, glass, ceramic tile, and other objects in the bathroom or kitchen, particularly as mentioned in ...
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### Why doesn't current pass through a resistance if there is another path without resistance?

I'll give a partial answer because the real answer probably involves heavy math and is beyond my current knowledge. I wish a condensed matter or solid state physicist would take over and either ...
Accepted

### Where does the sound we hear from short circuits come from?

The humming in most cases comes from the source being AC. Compare the frequency of the humming with a 100 or 120 Hz Tone (depending on where you are) and you will find them to be similar. The tone ...
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### Calculating equivalent resistance

Current follows the least resistance path when available. This is wrong. Recall the Ohm's Law $$V=IR\Rightarrow I\propto \frac{1}{R}\ \ \ \ \ \ \text{if V constant.}$$ If there are two resistance ...
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### Can grounding wrist prevent electrical shock?

DO NOT WORK ON ELECTRICAL MAINS UNLESS YOU ARE A PROPERLY TRAINED AND LICENSED ELECTRICIAN Seriously, this stuff can kill or maim you invisibly, without warning, and far faster than you can react to ...
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### Is there any current flow from a battery to the earth?

It doesn't matter whether or not the thing you are connecting is a battery. It doesn't matter whether or not the other thing is the Earth. If you have two conductive objects with no conductive path ...
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### Why do resistors heat up less than short circuited wires if resistors have higher resistance and therefore turn more voltage into heat?

Let's start with the relation $P=IV$ which says that power is proportional to the current times the voltage. Let's take as an example 2 resistors, one of resistance $R_1=100\Omega$ and one of ...
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### Why doesn't current pass through a resistance if there is another path without resistance?

An electric charge will experience a force if an electric field is applied. If it is free to move, it will thus move contributing to a current. This is what the basic idea of 'Electric Currents in ...
Accepted

### Why doesn't current pass through a resistance if there is another path without resistance?

This question has already been well answered, and in particular several of the correct answers referred to what you call "charge buildup" in the comments where you say: The "charge ...
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