Current on 20 Ohm Resistor: Circuit Homework

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SUMMARY

The discussion focuses on calculating the current through a 20 Ohm resistor in a circuit involving two 10 Ohm resistors and a 5 Ohm resistor. The user initially applied Kirchhoff's Voltage Law incorrectly, leading to an erroneous current calculation of 0.45 A instead of the expected value. By simplifying the circuit and recognizing the series and parallel configurations, the user was guided to reduce the circuit to two loops, allowing for a more accurate analysis. The final resolution involved correctly applying the principles of circuit reduction and loop analysis.

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Homework Statement


http://img65.imageshack.us/img65/4307/mymymyyw3.th.png
Find the current on the 20 ohm resistor.

Homework Equations


The Attempt at a Solution


Well, I'm fairly positive that the two 10 ohm resistors will transport the same amount of current so:

25V - I*25 - I2*10 = 0
25V + I3*5 - 10*I2 = 0
I = 2*I2 + I3

When I solve using those equations, I get I2 = 1.36 A and I = .45 A (I is double of what it should be).
Could anyone look at my equations and tell me what's wrong?
 
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Reduce the circuit as much as possible. You put the 5 ohm and 20 ohm in series already. There is also the 5 ohm and 10 ohm that are in parallel. If you reduce that you will then have a circuit with two loops. Then you will only have two unknowns to deal with.
 
Ok, now I've got it, thanks
 

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