A balanced bridge compares two divider nodes and reads zero when the node voltages match, so the meter becomes a null test. The 8 V and 0 V values here are exact ideal-divider results with an ideal non-loading meter; real bridges depend on resistor tolerance, source stability, input loading, temperature drift, and measurement uncertainty.
A bridge is balanced when two divider nodes have the same exact voltage. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
The left divider output is exact
The left divider output is 8 volts.
Vleft=8V
The right divider output matches
The right divider output is also 8 volts, so the bridge meter reads 0 volts. The bridge voltmeter is ideal and does not load the bridge.