Circuit question with two batteries and resistors in pa

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The discussion revolves around calculating the power dissipated by resistor R1 in a circuit with two batteries and resistors. The user attempted to analyze the circuit by defining currents and simplifying resistor values but encountered issues when substituting values into their equations. They specifically questioned why there would be any current flowing through R1, indicating confusion about the potential difference across it. The response emphasizes that the current through R1 is dependent on the potential difference across that resistor. Understanding the voltage across R1 is crucial for determining the current and subsequently the power dissipated.
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Homework Statement


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Q: What is the power dissipated by R1?

Homework Equations



Ohm's law: V = IR
Power: P = VI, I2R, V2/R
Kirchoff's circuit and voltage laws

The Attempt at a Solution



I assumed the currents were I1 traveling rightwards from the top battery, I2 rightwards from the second battery, and came together to make I3 for the bottom branch. The bottom resistor pair I simplified to 10/7 Ohms. From here I assume I have to set up simultaneous equations to solve for I1.

I used the equation for the bottom branch 1.5V - 10/7 * I3 = 0 to get I3 = 1.05A.

I subbed this into the equation for the outer loop 1.5 - 3I1 - 10/7I3 = 0. However plugging 1.05A into this gave me 0 for I1...

I feel like I'm way off the mark..
 
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Why would there be any current flowing in R1?
 
oz93666 said:
Why would there be any current flowing in R1?
Indeed!

The current through R1 is determined by the PD across R1. So ask yourself: what is the P.D. across R1?
 
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