Finding Power using Kirchhoff's rule

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Discussion Overview

The discussion revolves around calculating the power delivered to a resistor (R1) in a circuit using Kirchhoff's rules. Participants explore the application of circuit analysis techniques, including the use of equivalent resistances and loop equations.

Discussion Character

  • Homework-related
  • Mathematical reasoning

Main Points Raised

  • The initial poster presents a problem involving resistors and voltage sources, seeking help with their calculations.
  • One participant requests to see the initial poster's working to provide assistance and inquires about expected answers.
  • The initial poster later describes their approach to finding the equivalent resistance of R2 and R3 and outlines the loop equations they used to solve for currents.
  • Another participant expresses agreement with the outlined approach and asks for the calculated power value.
  • Two participants report obtaining the same power value of 1250 W, indicating their calculations align with each other.
  • One participant notes the importance of verifying calculations despite theoretical correctness, suggesting a cautious approach to practical applications.

Areas of Agreement / Disagreement

Participants generally agree on the approach to solving the problem and arrive at the same power calculation. However, the initial poster's initial confusion and request for help indicate that there may have been uncertainty in the early stages of the discussion.

Contextual Notes

The discussion does not clarify the assumptions made in the calculations or whether all necessary steps were shown, leaving some details of the mathematical process unresolved.

Who May Find This Useful

Students or individuals studying circuit analysis, particularly those interested in applying Kirchhoff's rules to calculate power in electrical circuits.

skelder
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Homework Statement



Calculate the power delivered to R1
R1=2.00 Ω, R2=4.00 Ω, R3=4.00 Ω, R4=2.00 Ω, E1=60.0 V and E2=30.0 V.

See current in Attachments:

Homework Equations



P=IV=V^2/R

The Attempt at a Solution



Made R2 and R3 equivalent resistors and then used different loops to solve for current. I end up with a current of 0. HELP!
 

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Can you show your working so we can assist you in finding an answer. Do you know which answers you are supposed to get?
 
I figured it out thanks anyways.

Find the equivalent resistance of R2 and R3. Then use two loops:

I' is the current flowing through the equivalent resistance

1) E1 - R1I1 + ReqI' = 0

2)E2 - R4I4-I'Req = 0

3) I1+I'=I4

sub eqn 3 in 2 and solve for I'

Now sub this in 1 and solve for I1

Now use I1 and R1 to get power
 
Looks good!

What did you get for the Power?
 
I got 1250 W
 
Me too!

Just wanted to check the numbers despite the theory being sound, since sometimes crazy things happen between the theory and the practice.
 

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