Bridge Circuit

[Martin]

In the circuit shown here (http://www.his.com/~mhtesler/BridgeConfiguration.jpg), what value of R0 will result in RAB being equal to R?

[Galileo]

I don't think any current will flow through R0. So it doesn't matter what value it has.
R_{AB} will be R regardless.

[Gokul43201]

Very true...