Resistors and circuit requirements

[mppaki]

1. A student needs a 5Ω and 10Ω resistor for a circuit, but she only has a dozen 20Ω resistors. Does she need to buy new resistors or can she meet the circuits requirements with the resistors that she has? Explain (be specific!).

2. I honestly don't know any equation to use...



3. What I'm thinking is that the girl can make a circuit with 2 parallel circuits like this one in this picture below. And by finding the req for each one, one would be 5Ω and the other would be 10Ω

 

[overt26]

You are on the right track. It only remains to work out how you make each of the required resistors from 20 ohm values.

A Hint: For example if you put 2 x 100 ohms in parallel you get 50 ohms.

So how many 20 ohms in parallel would make 10 ohms? Once you get a handle on that idea, it should be a simple matter to work out to get 5 ohms (1/4 of 20).

 

[mppaki]

alright thanks a lot overt26