Introduction to Wheatstone Bridge
The Wheatstone bridge is a fundamental circuit used for measuring electrical resistance. It is particularly effective for determining unknown resistances by balancing two legs of a bridge circuit.
How Does the Wheatstone Bridge Work?
- The bridge consists of four resistors arranged in a diamond shape.
- Two resistors (R1 and R2) are in one leg, and two (R3 and the unknown resistor Rx) are in the other leg.
- A galvanometer is connected between the two junctions of the resistors.
Balancing the Bridge
- The bridge is balanced when no current flows through the galvanometer. This occurs when the ratio of the resistors is equal:
R1/R2 = Rx/R3
- At this point, the voltage across the galvanometer is zero, indicating that the potential difference is equal on both sides.
Calculating Resistance
- To find the value of the unknown resistor (Rx), the equation can be rearranged:
Rx = (R3 * R1) / R2
- This formula allows for precise measurement of resistance, making the Wheatstone bridge a valuable tool in laboratories and various applications.
Applications of Wheatstone Bridge
- Used in calibration of measuring instruments.
- Employed in strain gauges for measuring deformation.
- Utilized in temperature sensors.
Conclusion
In summary, the Wheatstone bridge is primarily used to measure resistance, making option 'D' the correct answer. Its design and principle of operation allow for accurate resistance measurements, which is crucial in various scientific and engineering fields.