Current through short-circuit inductor

In summary: I stand corrected if the inductor is consider perfect conductor. But as I said, it real life that is hard to get.
  • #1
Fairouz84
1
0
Hi,
If we short circuit a simple basic inductor in an AC system, what happen to the inductor and the current at the branch?

Inductor do not has resistance, so do the short circuit line.
Does the current will divide equally through each branch and only some lagging at the inductor branch ?

Or is it that the current will only go through the short circuit line?

Thanks for your interest :smile:
 
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  • #2
If it is an AC circuit, the inductor will have some reactance but a perfect short circuit will have no resistance or inductance.

So, in this case all the current would go through the short circuit.
 
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  • #3
An inductor with its leads shorted is analogous to a capacitor with its leads open. Whatever current was flowing through the inductor when the leads were shorted (initial condition) will continue to flow around this loop forever. This is analogous to opening the leads of a capacitor, it will simply hold, indefinitely, whatever voltage was across its plates when the leads were opened. Both the shorted inductor and the open capacitor are used as energy storage in high energy experiments (using superconductors in the inductor case).
 
  • #4
Yes, the lower the resistance the shorting line, the longer it takes for the current to die down. But there is no perfect conductor in normal situation, so the current will die down and all current will eventually goes through the wire not the inductor.
 
  • #5
yungman said:
Yes, the lower the resistance the shorting line, the longer it takes for the current to die down. But there is no perfect conductor in normal situation, so the current will die down and all current will eventually goes through the wire not the inductor.

For this setup I think you have to assume that the Inductor also has zero resistance - so the current ( from the external circuit) will be shared by both.
But, yet again, the results get crazy when we start to use truly ideal components.
 
  • #6
sophiecentaur said:
For this setup I think you have to assume that the Inductor also has zero resistance - so the current ( from the external circuit) will be shared by both.
But, yet again, the results get crazy when we start to use truly ideal components.

Yes, I stand corrected if the inductor is consider perfect conductor. But as I said, it real life that is hard to get. A simple short is going to be much lower resistance than a coil and current dominates in the short circuit side.
 
  • #7
sophiecentaur said:
For this setup I think you have to assume that the Inductor also has zero resistance - so the current ( from the external circuit) will be shared by both.
But, yet again, the results get crazy when we start to use truly ideal components.

The inductor at least has inductance, so some inductance has infinitely greater impedance than a perfect short circuit in an AC circuit.
 
  • #8
Getting too theoretical here, in any normal sense, the resistance of the inductor is higher than the dead short and most current goes through the dead short. Super conductor is not practical in common cases.

call me ignorant, have we achieve true super conductor yet? I mean that the resistance of a 1mm diameter wire has the same resistance of a 1m diameter wire per long length where both are 0.000000000000000000000000000000000...ohms?
 
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  • #9
Just using the assumptions in the question, the inductor has no resistance but it does have inductance and therefore impedance in an AC circuit.

The short circuit has no resistance

Just on those assumptions, then ALL the AC current will go through the short circuit. Some impedance is infinitely greater than no impedance.

If you change the assumptions, then the result will be different.
 
  • #10
vk6kro said:
Just using the assumptions in the question, the inductor has no resistance but it does have inductance and therefore impedance in an AC circuit.

The short circuit has no resistance

Just on those assumptions, then ALL the AC current will go through the short circuit. Some impedance is infinitely greater than no impedance.

If you change the assumptions, then the result will be different.

If short out the signal, you have no AC, you have no impedance in the inductor!:rofl:!

Sorry, I am just pulling your leg! Have a nice weekend.
 
  • #11
yungman said:
Getting too theoretical here, in any normal sense, the resistance of the inductor is higher than the dead short and most current goes through the dead short. Super conductor is not practical in common cases.

call me ignorant, have we achieve true super conductor yet?

Are we talking about a textbook problem here or a real application. If it is a real application you may need to describe the components, voltages, currents, and frequency in more detail.
I mentioned superconductor because I assumed this was a textbook problem with ideal components.
This is off-topic but, in fact, superconductors have *exactly* zero resistance. Check out the Wikipedia page.
 
  • #12
the_emi_guy said:
Are we talking about a textbook problem here or a real application. If it is a real application you may need to describe the components, voltages, currents, and frequency in more detail.
I mentioned superconductor because I assumed this was a textbook problem with ideal components.
This is off-topic but, in fact, superconductors have *exactly* zero resistance. Check out the Wikipedia page.

That's a good question, I don't know. I tend to think in real circuit, not theoretical zero resistance, current goes on forever when you short the inductor and all. I don't even take this post seriously anymore with the super conductor came in.
 
  • #13
the_emi_guy said:
Are we talking about a textbook problem here or a real application. If it is a real application you may need to describe the components, voltages, currents, and frequency in more detail.
I mentioned superconductor because I assumed this was a textbook problem with ideal components.
This is off-topic but, in fact, superconductors have *exactly* zero resistance. Check out the Wikipedia page.

The "zero resistance" of a superconductor is the same as the "zero resistance" of the lines on a schematic circuit diagram. Any 'real' superconducting conductor will be joined into a circuit with 'real' wires.

These concepts don't have a place when we're trying to talk about taking practical things as far as we can. There's always an R in there.
 

1. What is a short-circuit inductor?

A short-circuit inductor is a type of inductor that has a very low resistance and is designed to allow a large amount of electrical current to flow through it. It is often used in electronic circuits to limit the amount of current that passes through a specific component.

2. How does current flow through a short-circuit inductor?

When a short-circuit inductor is connected to a power source, current flows through it in the opposite direction of the voltage applied to it. This creates a magnetic field which stores energy in the form of electricity. As the current increases, the magnetic field also increases.

3. What happens when a short-circuit inductor is placed in a circuit?

When a short-circuit inductor is placed in a circuit, it acts as a barrier to the flow of current. This limits the amount of current that can pass through the circuit, protecting other components from being damaged by excessive current. The inductor also helps to stabilize the voltage in the circuit by storing and releasing energy as needed.

4. What are the advantages of using a short-circuit inductor?

One advantage of using a short-circuit inductor is that it helps to protect other components in a circuit from damage caused by excessive current. It also helps to stabilize the voltage in the circuit, which can improve the overall performance of the circuit. Additionally, short-circuit inductors are relatively inexpensive and can be easily integrated into electronic circuits.

5. Are there any limitations to using a short-circuit inductor?

One limitation of using a short-circuit inductor is that it can cause a delay in the response time of a circuit. This is because the inductor needs time to build up its magnetic field before it can limit the current flow. Additionally, short-circuit inductors have a limited capacity for storing energy, so they may not be suitable for high-power applications.

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