How do you find the equivalent resistance of a circuit?
Thanks in advance.

 

By reducing series and parallel combinations down to a single resistance between a pair of nodes.

 

sorry don't really get your explanation.. I was trying to solve this:

A 7 ohm, a 1 ohm, and a 10 ohm resistor are in series. This series combination is then in parallel with a 6 ohm resistor. The combination of four resistors is then in series with a 10.3 ohm resistor. A 20 V battery is used. What is the equivalent resistance?

If you can explain the above question, it'll be much appreciated

 

The best thing to do is draw it out. Just so you know, the battery voltage is a red herring.

Look up http://en.wikipedia.org/wiki/Resistor#Series_and_parallel_circuits for more info on the general concept.

 

okay so im using this:

what operation do you use with the R1 and R2.. (aside from the addition one).

 

okay so im using this:

what operation do you use with the R1 and R2.. (aside from the addition one).

On the numerator you multiply R1 by R2

 

You can also read the material on series and parallel circuits here in the AAC ebook.

hgmjr

 

okay so im using this:

what operation do you use with the R1 and R2.. (aside from the addition one).

Is this an algebra question? You just substitued R1, R2, and R3 into the equation and get Req.

 

thanks for all the help.. the answer is suppose to be 14.8 ohm..

 

the answer is 14.8

Show your work and then someone can tell you where you went astray.

 

I prefer to answer your PM in the open forum so others may benefit.

Your explanation of the question was just fine. I don't know how much plainer my answer could have been. In the thread above there is a relationship for two resistors in parallel. This relationship can be applied recursively to any number of resistors in parallel. There is also the following relation

For n resistors in parallel R1, R2, ..., Rn.
The total resistance Rt, is given by
 
1/Rt = 1/R1 + 1/R2 + ... + 1/Rn

If you really want to impress your friends at cocktail parties you can refer to this as adding conductances measured in mho which is ohm spelled backwards.

Another fun factoid is that in any parallel combination the total resistance is always strictly less than the smallest resistance on any branch.