Calculating Equivalent Resistance

[PennStateFan1]

Homework Statement

In the circuit shown in the figure, R1 = 3.23 Ω, R2 = 5.19 Ω, R3 = 23.1 Ω, and V = 10.7 V.

a) Determine a value for the equivalent resistance.

http://img651.imageshack.us/i/p074figure.png/

Homework Equations

Parallel is 1/R1+1/R2+1/Rn=1/Req
Series R1+R2+R3=Req

The Attempt at a Solution

I know how to calculate the equivalent resistance of the top part and the bottom part, which are the same, but how do you calculate the total resistance with the source between the two? Taking them in parallel is obviously wrong.

The equivalent resistance of the top part is 27.1 ohms if that helps explain it to me.

Thanks

 

[jhae2.718]

Resistors are in parallel if they have the same potential difference, and are in series if they have the same current.

Do either of these cases apply to the equivalent resistors you found for the top and bottom loops?

 

[PennStateFan1]

When I was putting them in parallel I was forgetting to do the 1/Req. Thanks for the advice, as I got the answer when I went back and tried again.