Posted by charlie on Monday, February 16, 2009 at 7:48am.
If I have a 9V circuit, with:
2 resistors in parallel; followed by:
2 single resistors in series;
and I calculate the effective R of the parallel pair (using 1/R=1/R1+1/R2); can i then add this value to the series resistors to get a total for the circuit? As in:
(1/R=1/R1+1/R2)+R3+R4 = Reff
If so, can I now use Ohm's Law to get the current flowing through the last single resistor?
Thanks

physics: Electricity/Resistance  bobpursley, Monday, February 16, 2009 at 7:54am
The way you did it in the formula, you added the reciprocal of the parallel resistance to R3 and R4.
Rparallel= (R1*R2/(R1+R2))
then add that to R3 and R4 
physics: Electricity/Resistance  charlie, Monday, February 16, 2009 at 7:57am
I get it. My text shows your formula, but recommends 1/R= 1/R1+1/R2 etc as easier! I'm with you. If the numbers match, is my thinking ok?

physics: Electricity/Resistance  charlie, Monday, February 16, 2009 at 7:59am
I forgot to say "take the reciprocal". Does that make more sense?