What is the balanced condition of wheatstone bridge circuit?

The balanced condition of a Wheatstone bridge circuit occurs when the potential difference between the points D and B is zero, that is, the galvanometer G reads zero. Under this condition, the bridge is said to be balanced.

In the balanced condition:

1. For Resistors:

- The ratio of the two adjacent arms is equal to the ratio of the opposite arms.

- R1/R2 = R3/R4

2. For Currents:

- The current flowing through the galvanometer is zero (I_g = 0).

3. For Voltages:

- The potential at points D and B is the same (V_D = V_B).

When the bridge is balanced, the ratio of the two known resistors (R1 and R2) is equal to the ratio of the two unknown resistors (R3 and R4), which can be calculated using Ohm's law:

R3 = R2 * (R4/R1)

Achieving the balanced condition is essential in measuring unknown resistances using a Wheatstone bridge circuit. By adjusting the variable resistor (R4) until the galvanometer reads zero, the values of the unknown resistor can be determined through the simple ratio equation mentioned above.