Trying to apply superposition method to circuit, not working

  • #1
TheKShaugh
22
0

Homework Statement



A double loop circuit is shown in the figure below.[/B]
FVTMCtE.png

The Emf
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x = 6.00 V and the Emf
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w = 19.00 V. Both are shown on the diagram. Calculate the power dissipated in the 6 Ω resistor located on the extreme right in the circuit.

Homework Equations



V=IR, P=VI

The Attempt at a Solution



I tried using superposition, where I replaced one battery with a short and solved for the voltage and current through the 6 ohm resistor, and the did the same by replacing the other battery with a short. The total current and voltage is the sum of the individual values. I plugged those final values into P=VI and got the wrong answer. Should this method work and I just did the work wrong or is there something I'm not aware of?
 
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  • #2
Sounds like you did it right but without your posting your work it's impossible for us to see where you might have gone wrong.
 
  • #3
TheKShaugh said:
I tried using superposition, where I replaced one battery with a short and solved for the voltage and current through the 6 ohm resistor, and then did the same by replacing the other battery with a short. The total current and voltage is the sum of the individual values. I plugged those final values into P=VI and got the wrong answer. Should this method work and I just did the work wrong or is there something I'm not aware of?
You cannot add power by superposition. You can compute current I by superposition:
I = I1 + I2.
Then P = I^2 R.
Or you could have computed V1 and V2 by superposition, then P = VI = (V1 + V2)(V1 + V2)/R.
 
  • #4
rude man said:
You cannot add power by superposition. You can compute current I by superposition:
I = I1 + I2.
Then P = I^2 R.
Or you could have computed V1 and V2 by superposition, then P = VI = (V1 + V2)(V1 + V2)/R.
DOH ! I assumed that's what he was doing but on rereading I see I just glossed over what he really said. Good catch.
 

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