Kirchhoff's rule for circuit with two batteries

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SUMMARY

The discussion centers on the application of Kirchhoff's rules to a circuit containing two unequal ideal voltage sources, specifically a 10V and a 5V source. The analysis reveals that the configuration leads to a contradiction, indicating that there is no solution to the circuit problem. This situation is classified as physically impossible, akin to a short circuit, where the currents approach infinity. The conclusion emphasizes that connecting unequal ideal voltage sources in parallel is invalid in circuit theory.

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  • Understanding of Kirchhoff's Voltage Law (KVL)
  • Familiarity with ideal voltage sources
  • Basic knowledge of circuit theory
  • Concept of short circuits in electrical circuits
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Homework Statement
I found a difficulty solving the following question using Kirchhoff's rules.
Relevant Equations
Kirchhoff's rules.
242850
 
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QuantumRose said:
Problem Statement: I found a difficulty solving the following question using Kirchhoff's rules.
Relevant Equations: Kirchhoff's rules.

View attachment 242850
Correct. The solution is: There is no solution.

To confirm this"
Taking the "outer" loop, in a clockwise direction (The loop containing only the 10V and 5V sources.) gives you:

10V − 5V = 0.

That's a contradiction.
 
SammyS said:
Correct. The solution is: There is no solution.

To confirm this"
Taking the "outer" loop, in a clockwise direction (The loop containing only the 10V and 5V sources.) gives you:

10V − 5V = 0.

That's a contradiction.
That's the thing that bothers me a lot. What is the physical reality that corresponds to no solution? does that mean no current anywhere or what?
 
QuantumRose said:
That's the thing that bothers me a lot. What is the physical reality that corresponds to no solution? does that mean no current anywhere or what?
No. It's a physically impossible situation if those are "ideal" sources of voltage. ##I_1 \to \infty## and ##I_3 \to -\infty## .

It's much like a short circuit.
 
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SammyS said:
No. It's a physically impossible situation if those are "ideal" sources of voltage. ##I_1 \to \infty## and ##I_3 \to -\infty## .

It's much like a short circuit.
Thank you!
 
This is one of the invalid connections in circuit theory. You can't connect two unequal ideal voltage sources in parallel and two unequal ideal current sources in series.
 
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cnh1995 said:
This is one of the invalid connections in circuit theory. You can't connect two unequal ideal voltage sources in parallel and two unequal ideal current sources in series.
This clears my mind, thank you
 
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