# Simple net resistance problem

1. Feb 19, 2016

### rkum99

1. The problem statement, all variables and given/known data

https://wcl.unr.edu/bbcswebdav/pid-634340-dt-content-rid-2875167_1/xid-2875167_1

So I am given the above image, and I am told to calculate the voltage in the circuit.

2. Relevant equations

V = IR
R_net = (1/R_1 + 1/R_2 + ... + 1/R_n)^-1 for parallel resistors

3. The attempt at a solution

So with a lot of these sort of problems, my biggest challenge is redrawing the circuit into something that I can more intuitively understand. However, I'm having a fair bit of trouble understanding what exactly is going on here - would the open wires with no resistors produce short circuits?

Once I can find the net resistance, the problem is straightforward: V = IR and plug and chug.

Turns out that if I treat all three resistors as in parallel I get the right answer, but I cant figure out how the above diagram could be converted into a simple 3 resistors in parallel.

Any help is appreciated.

2. Feb 19, 2016

### Staff: Mentor

3. Feb 19, 2016

### rkum99

4. Feb 19, 2016

### Staff: Mentor

It is preferable to UPLOAD an image and make it visible in the thread so that helpers do not have to follow a link in order to see it.

5. Feb 19, 2016

### cnh1995

Remove the middle 30Ω. What do you get?

6. Feb 19, 2016

### Staff: Mentor

Starting at terminal 'a', use different coloured pencils to trace each independent path that current can follow to get to 'b'.