Basic circuits problem, more information posted below shortly.

Question

mendicant_bias · Answer

http://i.imgur.com/HNgHzSj.png

mendicant_bias · Answer

Wouldn't diagrams (a) and (b) have an effectively equal resistance, assuming an ideal wire?I'm guessing the difference would be between (a) and (c).

mendicant_bias · Answer

@ganeshie8 , are you decent with circuits stuff at all?

mendicant_bias · Answer

The way I'd take a shot at the middle one, (b) would be treating the two wires as parallel, and do it like this:

radar · Answer

A. is parallel R1s in series with parallel R1s   This is R1/2 + R1/2 for a total resistance of R1 from A to B.

radar · Answer

For B. you have 2R1 (series of R1 + R1) in parallel with 2R1 again.
This provides a total effective resistance of R1 which is the resistance from A to B.

radar · Answer

Do you get the drift?   C.  Is like the first 2, you can ignore R2 as you can see from the first two, a short (0 Ohms) or infinite  (open) resistance between the junction of the R1s had no impact for the total resistance.  That is because the bridge is balanced.|dw:1417801055172:dw|
The potential at x and y are the same so no matter whats is placed between x and y, short, open, or R2, will affect the total resistance between A and B, it is also R1 as in the first two.