Electrician or Engineer question about circuits?

Question

If I am to calculate total parallel resistance for the following parallel resistive circuits, would I simple add them to get Total Resistance?

R1-1200 ohms

R2-1100 ohms

R3-900 ohms

Total Resistance is 3200 ohms ? Is that correct?

And would it be the same if I were to calculate total resistance for just 2 resistors? R1+R2=Total Resistance?

Thanks!!

Answer 1

If your resistors were in series, you would add them.

Since they are in parallel, there is LESS resistance since there are more paths for the electrons to go.  To find out how much, use this equation:

1/Rtotal = 1/R1 + 1/R2 + 1/R3

              =1/1200 + 1/1100 + 1/900

              = ~0.00285

Rtotal = ~350

For 2 Resistors, it would just be:

1/Rtotal = 1/R1 + 1/R2