Wheatstone Bridge

The above circuit combination is called a wheatstone bridge circuit. It is a combination of 4 Resistors connected to a power source in above manner.

Balanced Bridge

Balanced bridge is a condition in which the flow of current in the central galvanometer is ZERO. Such a condition can be achieved by a specific combination of all 4 resistor values.

Calculation of Resistor Values for balanced Wheatstone Bridge

For Balanced whetston bridge, Ig (current throgh Galvanometer ) should be zero.

Applying Loop rule in first loop:  


Applying Loop rule in second loop with condition that  and :  


Finally we arrive at equation : 

Thus for a balanced Wheatstone Bridge condtion to be achieved, all four Resistors should be such that 

Related Tutorials