Kirchhoff's rule for circuit with two batteries

In summary, Kirchhoff's rules are used to solve circuit problems. However, in some cases, there may be no solution, as seen in the example given where the equations lead to a contradiction. This is a physically impossible situation and is similar to a short circuit. It is important to note that certain connections in circuit theory, such as unequal ideal voltage sources in parallel and unequal ideal current sources in series, are invalid and cannot be solved using Kirchhoff's rules.
  • #1
QuantumRose
11
1
Homework Statement
I found a difficulty solving the following question using Kirchhoff's rules.
Relevant Equations
Kirchhoff's rules.
242850
 
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  • #2
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.
 
  • #3
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?
 
  • #4
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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  • #5
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!
 
  • #6
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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  • #7
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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What is Kirchhoff's rule for circuits with two batteries?

Kirchhoff's rule, also known as Kirchhoff's voltage law, states that the sum of all voltages around a closed loop in a circuit must equal zero. This means that in a circuit with two batteries, the total voltage supplied by one battery must be equal to the total voltage supplied by the other battery.

How do you apply Kirchhoff's rule to a circuit with two batteries?

To apply Kirchhoff's rule to a circuit with two batteries, you must first determine the direction of current flow in the circuit. Then, as you move around the circuit in a loop, you must take into account the polarity of each battery and whether the current is flowing towards or away from the battery. The sum of all voltages in the loop should equal zero.

Why is Kirchhoff's rule important in circuit analysis?

Kirchhoff's rule is important in circuit analysis because it allows us to calculate the voltage and current at any point in a circuit. It also helps us understand how different components in a circuit affect each other and how the overall circuit operates.

Can Kirchhoff's rule be applied to circuits with more than two batteries?

Yes, Kirchhoff's rule can be applied to circuits with any number of batteries. The same principle applies - the sum of all voltages around a closed loop must equal zero.

Are there any limitations to Kirchhoff's rule in circuits with two batteries?

One limitation of Kirchhoff's rule in circuits with two batteries is that it assumes ideal conditions, such as no resistance in wires and batteries with no internal resistance. In real circuits, there will always be some resistance and internal resistance, so the voltage may not be exactly zero when applying Kirchhoff's rule.

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