2nd Kirchhoff's law for all passive elements

In summary, the 2nd Kirchhoff's law for this circuit is that the sum of the voltages around a loop is zero.
  • #1
Jhenrique
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How would be the 2nd Kirchhoff's law for this circuit here:

attachment.php?attachmentid=70425&stc=1&d=1402186250.png


I'm asking because I don't know how is the behavior of the inductor, capacitor and current source wrt the 2nd Kirchhoff's law...
 

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  • #2
Kirchhoff's 2nd law states that the sum of the voltages around a loop is zero. It also applies to inductors and capacitors so..

VI + VR + VL + VC = 0

The voltage (particularly on Inductors and capacitors) is time dependant but the above still applies at any instant in time.
 
  • #3
CWatters said:
Kirchhoff's 2nd law states that the sum of the voltages around a loop is zero. It also applies to inductors and capacitors so..

VI + VR + VL + VC = 0

The voltage (particularly on Inductors and capacitors) is time dependant but the above still applies at any instant in time.

And if I add a voltage source in series in this circuit, the equation will be so:

VI + VR + VL + VC = VV

Yeah!?
 
  • #4
Jhenrique said:
And if I add a voltage source in series in this circuit, the equation will be so:

VI + VR + VL + VC = VV

Yeah!?

Yeah!
 
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  • #5
Yes. Although it might be better to write it as..

VI + VR + VL + VC - VV = 0

Did you realize you may have implied a different orientation for the additional voltage source VV?
 

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  • #6
or if you prefer
 

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  • #7
CWatters said:
Yes. Although it might be better to write it as..

VI + VR + VL + VC - VV = 0

Did you realize you may have implied a different orientation for the additional voltage source VV?

CWatters said:
or if you prefer

Interesting and confused!
 
  • #8
But I don't think so... I place in the left side of the equation the potential difference that favors the circulation of the current and I place in the right side the potential differences opposes the circulation of the current. I can't think in another way more intuitive...
 
  • #9
It's not always obvious if a "voltage" opposes or increases the current. Best practice is to mark your diagram in a consistent way, then go around each loop summing all the voltages. Then solve any simultaneous equations (eg for circuits with multiple loops). You may well find some unknown voltages turn out -ve when you were expecting them to be +ve.
 

Related to 2nd Kirchhoff's law for all passive elements

What is 2nd Kirchhoff's law for all passive elements?

2nd Kirchhoff's law for all passive elements, also known as Kirchhoff's voltage law, states that the algebraic sum of all voltages in a closed loop circuit is equal to zero. This means that the total voltage drop across a circuit must be equal to the total voltage supplied.

What is the significance of 2nd Kirchhoff's law in circuit analysis?

2nd Kirchhoff's law is crucial in circuit analysis as it allows us to determine the unknown voltages in a circuit by using the known voltages and the law's equation. It also helps in verifying the accuracy of the circuit analysis since it is based on the conservation of energy.

Can 2nd Kirchhoff's law be applied to all types of circuits?

Yes, 2nd Kirchhoff's law can be applied to all types of circuits, as long as they contain only passive elements such as resistors, capacitors, and inductors. It does not apply to circuits with active elements like transistors or diodes.

Can 2nd Kirchhoff's law be violated in a circuit?

No, 2nd Kirchhoff's law cannot be violated in a circuit. This law is based on the fundamental principle of conservation of energy, and any violation of it would go against the laws of physics.

How is 2nd Kirchhoff's law related to the principle of superposition?

2nd Kirchhoff's law is related to the principle of superposition in that it allows us to analyze complex circuits by breaking them down into smaller, simpler circuits, and applying the law to each of them. This principle is helpful in solving circuits with multiple voltage sources or complex configurations.

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