Wheatstone Bridge
Balance a four-resistor bridge and compare midpoint voltages with an ideal voltmeter.
Free theory articleBalance a four-resistor bridge and compare midpoint voltages with an ideal voltmeter.
Concept & interpretation
The Wheatstone Bridge is a circuit used to measure unknown electrical resistances or detect small changes in resistance by balancing two legs of a bridge circuit, one of which includes the unknown component.
Interactive Experiment
Explore this concept interactively in the Wheatstone Bridge module.
- Set Source voltage V to 12.
- Set Top-left resistance R1 to 4 and Top-right resistance R3 to 1.
- Set Bottom-left resistance R2 to 2 and Bottom-right resistance R4 to 2.
- Observe that the bridge is unbalanced (Balanced: False). The left midpoint is at 4V, while the right midpoint is at 8V, causing a meter reading of -4V.
- Change Top-left resistance R1 to 1 to match R3. Notice how the voltages equalize to 8V on both sides, bringing the meter reading to 0V and balancing the bridge.