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Resistors - Finding the Current

Hi. Can someone please help me with the following problem?

I'll try to draw the circuit (with battery and 4 resistors), but I don't know if all the spacing will come out right. The "///" are resistors.

Basically, it's a circuit with a 15-V battery and 4 resistors. First you hit R1, which = 11 ohms. Then there are two paths -- path #1 contains R2=7.5 ohms; path #2 contains 2 resistors in series, R3=6.2 ohms and R4 = 12 ohms. R3 and R4 are in parallel with R3.

R3=6.2 ohms
| -----------------////-----|
| | |
| | |
| / /
15V / R2=7.5 / R4=12 ohms
| / ohms /
| | |
| | |
R1=11 ohms

The questions asks us to find the current through each resistor using the rules for series and parallel.

The answers are:
I1 = 0.92 A
I2 = 0.65 A
and I(R3 + R4) = 0.27

But I don't understand why I wouldn't use the equation I1 = V/R1, I2 = V/R2 etc. for these. Can you please explain why I don't use that equation, and also what I should be using here?

The second part of the question asks us to find the current through each resistor using Kirchoff's rules. Can you show me that? I'm still having trouble with Kirchoff.

Thank you.

Solution Preview

Hello and thank you for using Brainmass!
The solution is attached below in two files. the files are identical in content, only differ in format. The first is in MS Word XP Format, while the other is in Adobe pdf format. Therefore you can choose the format that is most suitable to you.
Though the pdf file is 326K and the Word document is 649K (lots of graphics).

As to your initial ...

Solution Summary

The solution is given with explanations and diagrams and two references.