- A Wheatstone bridge is a type of electrical circuit used to measure an unknown resistance.
- It consists of four resistors connected in a diamond pattern, with a known voltage applied across the center of the diamond and the output voltage measured at the points on either side.
- The bridge is balanced when the ratio of two of the resistors is equal to the ratio of the output voltages, allowing the unknown resistance to be calculated.
The balancing condition of a Wheatstone bridge can be expressed mathematically as follows:
Vab / Vcd = R2 / R1
Where:
- Vab is the voltage difference between points A and B,
- Vcd is the voltage difference between points C and D,
- R1 is the resistance of resistor 1, and
- R2 is the resistance of resistor 2.
- In a balanced Wheatstone bridge, the voltage difference between points A and B is equal to the voltage difference between points C and D, meaning that the ratio of R2 to R1 is equal to the ratio of Vab to Vcd.
- This balance allows for the accurate determination of an unknown resistance in the circuit.