1. What is an Unbalanced Wheatstone Bridge?

An unbalanced Wheatstone bridge is a circuit used to measure unknown electrical resistance by comparing it with known resistances. When the bridge is unbalanced, the voltage difference can be measured and used to calculate the unknown resistance or other parameters.

2. How Does the Calculator Work?

The calculator uses the unbalanced Wheatstone bridge formula:

Where:

• \( V \) — Source voltage (V)
• \( R_x \) — Unknown or variable resistance (Ω)
• \( R_3 \) — Known resistance in series with R_x (Ω)
• \( R_2 \) — Known resistance in the other arm (Ω)
• \( R_1 \) — Known resistance in series with R₂ (Ω)

Explanation: The formula calculates the voltage difference between the two voltage dividers in the bridge circuit.

3. Applications of Wheatstone Bridge

Details: Wheatstone bridges are widely used in strain gauges, temperature sensors, light detectors, and other precision measurement applications where small resistance changes need to be detected.

4. Using the Calculator

Tips: Enter all resistance values in ohms (Ω) and source voltage in volts (V). All values must be positive numbers. The calculator will compute the output voltage across the bridge.

5. Frequently Asked Questions (FAQ)

Q1: What is a balanced Wheatstone bridge?
A: When the ratio R₁/R₂ = R₃/R_x, the bridge is balanced and V_out = 0.

Q2: How sensitive is the bridge circuit?
A: Sensitivity depends on the voltage source and resistor values. Higher voltage and matched resistances increase sensitivity.

Q3: Can this be used to measure very small resistance changes?
A: Yes, Wheatstone bridges are excellent for detecting minute resistance changes, especially when used with amplifiers.

Q4: What are common sources of error?
A: Lead resistance, temperature effects, and noise can affect measurements. Four-wire measurements help reduce errors.

Q5: Can I use this to find an unknown resistance?
A: Yes, by setting V_out = 0 (balancing the bridge), you can solve for R_x = R₃ × (R₂/R₁).