Calculating the currecnt of a circuit

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The discussion revolves around calculating the current through three resistors (R(1) = 1Ω, R(2) = 2Ω, R(3) = 3Ω) with driving voltages V(1) = 1V and V(2) = 2V. The user derived three equations based on Kirchhoff's laws to express the relationships between the currents and voltages in the circuit. After simplifying these equations, the user calculated the current I(3) to be approximately 1.37 A. Another participant in the discussion confirmed the equations but questioned whether the calculated currents were consistent, as only I(3) was provided. The conversation emphasizes the importance of verifying all current values in circuit analysis.
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Homework Statement



What current flows through the resistors R(1) = 1Ω, R(2) = 2 Ω and R(3) = 3 Ω, if the driving voltages are V(1) = 1V and V(2) = 2V?

Picture:
http://item.slide.com/r/1/151/i/lvtwIwH-0j8A8o-XAKDtPRQO1eHAb4Ik/

Homework Equations



V= RI → I= V/ R

The Attempt at a Solution



V(1)= I(2)R(2) + I(1)R(1)
V(2)= I(3)R(3) – I(2)R(2)
I(1)= I(2) + I(3)

- From what I stated above, I conclude three equations:

1) V(1) = I(2)R(2) + [(I(2) + I(3))*R(1)]
2) V(2)= I(3)R(3) - I(2)R(2)
3) V(1)= [I(2)*( R(1) + R(2))] + I(3)R(1)

- I combined the three equations and simplify for the current that goes through ALL resistors, which in our case is I(3):

I(2)= (I(3)R(3) - V(2))/ R(2)
V(1)R(2)= [(I(3)R(3) – V(2))/ R(2))*(R(2) + R(1))] + I(3)R(1)R(2)
(V(1)R(2))/ (R(2) + R(1))= (I(3)R(3)) + [I(3)R(1)R(2))/ (R(2) + R(1))]
I(3)*[R(3) + (R(1)R(2)/ (R(2) + R(1))]= [V(1)R(2)/ (R(2) + R(1))] + V(2)

I(3)= [(V(1)R(2)/ (R(2) + R(1)) + V(2)] / [R(3)* (R(1)R(2)/ (R(2) + R(1))]
I(3)= 1.37 A

Are my calculations correct?
Thank you for helping!:smile:
 
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mmoadi said:

The Attempt at a Solution



V(1)= I(2)R(2) + I(1)R(1)
V(2)= I(3)R(3) – I(2)R(2)
I(1)= I(2) + I(3)

I agree with these equations. Are your values for the currents consistent with them? You only gave I3 in your solution.
 
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