Homework Help: Need help finding unique resistor combinations

1. Apr 6, 2009

tiger00

Need help finding unique resistor combinations!!!

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

Amps = 30, 45, 60, 70
Voltage = 600 to 700, 600 to 800, 400 to 600
I have three typres of resistors 3 ohm, 5 ohm, 10 ohm
I have to find 17 combinations of resistors to work with the given amps and volts. The resistors all have to be differnet values(you cant use 2-3 ohm resistors, 2-5 ohm resistors or 2-10 ohm resistors.) The resistors can be in parallel or in a series.

2. Relevant equations

I=V/R

2. Apr 6, 2009

LowlyPion

Re: Need help finding unique resistor combinations!!!

Welcome to PF.

Sorry, I don't really understand your problem. What 17 combinations? I only see 12 combinations of voltage ranges and currents. Maybe if you could supply more information?

3. Apr 6, 2009

tiger00

Re: Need help finding unique resistor combinations!!!

That is my issue too....the teacher gave us the three different voltage ranges, the 4 different amperages, and we were told that we can use 3, 5, and 10 ohm resistors. She said that we have to find 17 combinations of using the resistors. Ex. I could use a 3,5,10 ohm resistor one time in a series. I could use a 3,5,10 the next time in parallel...as long as the I=V/R hold true.....

4. Apr 6, 2009

LowlyPion

Re: Need help finding unique resistor combinations!!!

In that case then just make a table of all the resistor combinations you can make. You have 3 single resistors alone, you have 3 pairs in ||, 3 pairs in series alone, you have 3 more with 1 in || 2 in series, etc. Basically all combinations possible.

Then figure the equivalent resistances that each makes, and see which ones fit which V and I.