Is it Possible for a Short Circuit to Contradict Voltage in a Parallel Circuit?

In summary, the conversation discusses the possibility of connecting an ideal voltage source with a superconducting wire. It is determined that this is impossible due to the logical contradiction between an ideal voltage source and an ideal short, and the fact that superconductors have a maximum current limit. Additionally, the use of ideal voltage sources in circuit analysis is discussed and it is suggested to consider the inductance of the short in this scenario.
  • #1
Kevin J
57
2
Assume a superconducting parallel circuit being shorted, a 10V ideal battery, and a 5 Ohms resistor connected on one of its path. This means the shorted path has a 0 Ohm resistance, which also means it has no potential difference, how is this even possible if voltage across in a parallel circuit should be the same, in this case one path has 10V, the other one has 0V?
*
Or is an ideal voltage source/battery is impossible to be connected with a superconducting wire?
 
Physics news on Phys.org
  • #2
Ideal voltage sources that can source unlimited current do not exist. Superconductors have a current limit.
 
  • #3
+1

Ideal voltage sources are simplified models of real voltage sources, models in which the internal resistance is assumed to be zero so its effect can be ignored. It's up to you to decide if it's reasonable to use that model in any particular circuit.

You might also like to think about what happens you open circuit an ideal current source (compared to a real current source).
 
  • #4
Kevin J said:
Or is an ideal voltage source/battery is impossible to be connected with a superconducting wire?

Regarding "Zero electrical DC resistance" questions, it is always better to physically rethink analyzing the circuit under constant current conditions in the following sense:

"The simplest method to measure the electrical resistance of a sample of some material is to place it in an electrical circuit in series with a current source I and measure the resulting voltage V across the sample. The resistance of the sample is given by Ohm's law as R = V / I. If the voltage is zero, this means that the resistance is zero." (from https://en.wikipedia.org/wiki/Superconductivity#Zero_electrical_DC_resistance)
 
  • #5
Kevin J said:
Or is an ideal voltage source/battery is impossible to be connected with a superconducting wire?
It is impossible. It is a logical self contradiction since the ideal voltage source asserts ##V\ne 0## and the ideal short asserts ##V=0##. The one contradicts the other.

Since ideal voltage sources don’t exist that is the assumption that usually fails and the current will be limited by the real source’s internal resistance. However, you could also consider the inductance of the short, which can be nonzero even for a superconductor. Superconductors also have a maximum current density at which point they stop superconducting and become resistive.
 

1. What is a short circuit contradiction?

A short circuit contradiction is a logical fallacy where an argument or statement contradicts itself due to a reliance on circular reasoning or faulty logic. It is often used in debates or discussions to point out flaws in an opponent's argument.

2. How does a short circuit contradiction occur?

A short circuit contradiction occurs when an argument or statement relies on itself to prove its own validity, or when it uses faulty logic to support its conclusion. This often leads to a circular reasoning or a logical paradox that undermines the credibility of the argument.

3. What are some examples of short circuit contradictions?

One example of a short circuit contradiction is the statement "I always lie." This statement cannot be true because if it were true, then the person saying it would not always be lying. Another example is the statement "This statement is false." This statement creates a paradox because if it were true, then it would also be false, and if it were false, then it would also be true.

4. How can a short circuit contradiction be avoided?

To avoid a short circuit contradiction, one must carefully examine their arguments and statements to ensure that they are not relying on circular reasoning or faulty logic. It is important to use evidence and sound reasoning to support a conclusion, rather than relying on the conclusion to prove itself.

5. Why is it important to be aware of short circuit contradictions?

Being aware of short circuit contradictions is important because it allows one to critically evaluate arguments and identify weaknesses or flaws in reasoning. It also helps individuals to avoid using faulty logic in their own arguments and to communicate more effectively and persuasively.

Similar threads

Connect parallel batteries with wrong poles
    • Electrical Engineering
Replies
17
Views
1K
B Are these AC circuits different? And does grounding change the voltage?
    • Other Physics Topics
Replies
7
Views
1K
B How a Secondary Resistor affects the Transformer Primary Side?
    • Other Physics Topics
Replies
6
Views
17K
B Batteries in Parallel Arrangement
    • Other Physics Topics
Replies
11
Views
2K
Ohm's Law - Finding Source Voltage
    • Introductory Physics Homework Help
Replies
3
Views
533
Parallel MOSFET safety diagnostics circuit
    • Electrical Engineering
Replies
1
Views
906
Engineering How do I find Vth with the node voltage method?
    • Engineering and Comp Sci Homework Help
Replies
10
Views
2K
Why do the headlights on the car become dim when the car is starting?
    • Introductory Physics Homework Help
Replies
4
Views
266
Understanding Short Circuit Current Paths in Electrical Circuits
    • Introductory Physics Homework Help
Replies
4
Views
881
What determines the time constant in a parallel R and C circuit?
    • Electrical Engineering
Replies
21
Views
1K

Hot Threads

Recent Insights

Back
Top