# Wheat Stone Bridge - Redone

1. Oct 23, 2011

### modulus

When we talk of a Wheat Stone Bridge, we say that if the two pairs of resistances in the top row, and the two in the bottom row have the same ratio of the value of their resistances, then no current flows through the connecting wire in the middle.

But, that applies if the current is entering from one junction, and leaving the other. What happens, if the electric field in the wires (battery) originates from someplace else, like the original position of the galvanometer? And the galvanometer is placed where the battery was in the original circuit?

Will the galvanometer show any deflection?

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2. Oct 23, 2011

### Delta²

If you mean to switch positions between the battery and galvanometer then again the meter will not show anything. This is because the ratio of resistances in the switched configuration remains equal.
That is if $$\frac{R_1}{R_2}=\frac{R_3}{R_4}$$ is the ratio in the original configuration, then it is easy to see that $$\frac{R_1}{R_3}=\frac{R_2}{R_4}$$ which is the ratio in the switched configuration.