# Questions regarding DC circuits

1. May 8, 2008

### R A V E N

I have one confusing issue to resolve:

What is the resistance between points $$A$$ and $$B$$ in simple system illustrated in attachment?Wouldn`t be logical to assume that it is $$0$$,as current strives to flow through path with lowest possible resistance,if I understood it correctly?

Yes,I know that real transmission lines have some resistance,but in network anaylsis their resistance is considered to be equal to zero.

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Last edited: May 8, 2008
2. May 8, 2008

### stewartcs

You have a short circuit so what ever the resistance of the wire connecting point A and B.

CS

3. May 12, 2008

### misho

Yeah, it's zero assuming everything's ideal. Mathematically even, you have a wire ($$R=0$$) in parallel with a resistor ($$R=R_0$$). Then the parallel combination is:

$$R_{eq} = \frac{1}{ \frac{1}{0} + \frac{1}{R_0} } = \frac{1}{\infty + \frac{1}{R_0}} = 0$$

I should probably have put some limits in there to be mathematically correct, but you get the idea.

4. May 12, 2008

### R A V E N

Thanks to both of you!