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Wheatstone bridge is a
bridge
bridge
High voltage bridge
Power dissipation bridge
bridge
Quick Summary: The Wheatstone bridge is primarily classified as a D.C. bridge because it is fundamentally designed to measure unknown resistances using a stable D.C. excitation source. When the bridge is balanced, the potential difference between the galvanometer terminals is zero, allowing for precise resistance determination.
The Wheatstone bridge is primarily classified as a D.C. bridge because it is fundamentally designed to measure unknown resistances using a stable D.C. excitation source. When the bridge is balanced, the potential difference between the galvanometer terminals is zero, allowing for precise resistance determination.
RxтАЛ=R3тАЛтЛЕR1тАЛR2тАЛтАЛ тАФ Calculation of unknown resistance at null condition
IgтАЛ=0 тАФ Balancing condition for the galvanometer
The bridge consists of four arms arranged in a diamond configuration. When a D.C. source is applied, the bridge is balanced if the ratio of resistances in opposite arms is equal (R1тАЛ/R2тАЛ=R3тАЛ/R4тАЛ). In this state, no current flows through the central detector (galvanometer), meaning the bridge is independent of the detector's resistance.
Used for accurate measurement of medium-range resistances (1 ╬й to 100 k╬й).
Sensitive to changes in resistance due to the differential nature of the bridge.
Not suitable for extremely low resistance (contact resistance issues) or very high resistance (leakage issues).
High sensitivity and accuracy.
Simple circuit construction.
Null method provides independence from source fluctuations.
Requires manual adjustment for null balance.
Sensitivity decreases significantly when resistances are far from the balanced state.
Calibration of standard resistors.
Strain gauge instrumentation circuits.
Temperature measurement using RTDs (Resistance Temperature Detectors).
AC bridges (e.g., Maxwell or Schering bridge) are used for measuring impedance, capacitance, or inductance using an A.C. source.
The Wheatstone bridge is strictly a resistive bridge, making it incompatible with pure A.C. reactive measurements without complex modifications.
B is correct тАФ The Wheatstone bridge is a D.C. bridge configuration designed to measure unknown resistors by balancing a resistive network.
Always remember: A.C. bridges involve complex impedances (Z=R+jX), whereas D.C. bridges like the Wheatstone bridge rely solely on real resistances (R).