Kirchhoff's rule for circuit with two batteries

  • Thread starter Thread starter QuantumRose
  • Start date Start date
  • Tags Tags
    Batteries Circuit
Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
6 replies · 3K views
QuantumRose
Messages
11
Reaction score
1
Homework Statement
I found a difficulty solving the following question using Kirchhoff's rules.
Relevant Equations
Kirchhoff's rules.
242850
 
Physics news on Phys.org
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.
 
  • Like
Likes   Reactions: cnh1995 and QuantumRose
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.
 
  • Like
Likes   Reactions: berkeman and QuantumRose
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
 
  • Like
Likes   Reactions: berkeman