learn.howToCalculate
learn.whatIsHeading
The Wheatstone bridge is a circuit used to measure unknown electrical resistance by balancing two legs of a bridge circuit. R_unknown = R3 × (R2/R1).
الصيغة
At balance: R1/R2 = R3/Rx — solve for unknown Rx
- At
- R3/Rx — solve for unknown Rx — R3/Rx — solve for unknown Rx
- R1
- R3/Rx — solve for unknown Rx — R3/Rx — solve for unknown Rx
- R2
- R3/Rx — solve for unknown Rx — R3/Rx — solve for unknown Rx
- R3
- R3 value — Variable used in the calculation
- Rx
- Rx value — Variable used in the calculation
دليل خطوة بخطوة
- 1Four resistors arranged in a diamond (bridge) configuration
- 2A galvanometer in the centre detects current imbalance
- 3At balance: R1/R2 = R3/Rx — solve for unknown Rx
أمثلة محلولة
الإدخال
R1=100Ω, R2=200Ω, R3=150Ω
النتيجة
Rx = 300Ω
Bridge balanced when R1/R2 = R3/Rx
أخطاء شائعة يجب تجنبها
- ✕Assuming the bridge must be exact — modern circuits use operational amplifiers for nulling
- ✕Ignoring lead resistance in precision measurements
أسئلة شائعة
What is a Wheatstone bridge used for?
Precision measurement of resistance, strain gauges, temperature sensors (RTDs), and load cells.
What happens when the bridge is balanced?
No current flows through the galvanometer. The voltage across it is zero.
هل أنت مستعد للحساب؟ جرب الآلة الحاسبة Wheatstone المجانية
جربه بنفسك →