Wheatstone Bridge
Interactive Digital Learning by Kalviyogi Nagarajan, 369 Tesla Pvt Limited
What is a Wheatstone Bridge?
A Wheatstone bridge is a special electrical circuit used to measure unknown electrical resistance by balancing two legs of a bridge circuit.
It was invented by Samuel Hunter Christie in 1833 and improved and popularized by Sir Charles Wheatstone in 1843.
Interactive Wheatstone Bridge Simulation
Build Your Own Wheatstone Bridge
Components
Mode
Actions
Select a component from the left panel first
Real-World Applications
A meter bridge is a practical application of the Wheatstone bridge principle. It consists of a one-meter long wire with a uniform cross-section, which acts as two resistors in the bridge circuit.
How It Works:
- The meter wire forms two arms of the bridge (R₁ and R₂)
- A known resistance (R₃) and unknown resistance (R₄) form the other two arms
- A sliding contact moves along the wire until the galvanometer shows zero deflection
- The position of the contact gives the ratio of resistances
Everyday Example:
In school physics labs, students often use meter bridges to measure the resistance of components like resistors, thermistors, or light-dependent resistors (LDRs). It's like having a precise electrical ruler!
Example Problem
Problem:
The four arms of a Wheatstone bridge have the following resistances:
- AB = 100Ω
- BC = 10Ω
- CD = 5Ω
- DA = 60Ω
A galvanometer of 15Ω resistance is connected across BD. Calculate the current through the galvanometer when a potential difference of 10V is maintained across AC.