Objective: Measurement of self-inductance of an unknown coil.

This bridge circuit measures an inductance by comparison with variable standard self inductance. The connections for balance condition is shown in Fig. 1.

Fig. 1. Maxwell Inductive Bridge.

Let, L_{1}= unknown inductance of resistance R_{1}.

L_{2}= variable inductance of fixed resistance r_{2}.

R_{2}= variable resistance connected in series with inductor L_{2}.

R_{3}, R_{4} =known non inductive resistances.

At balance,

Resistor R_{3 }and R_{4} are normally a selection of values from 10, 100, 1000. and 10,000 . r_{2} is a decade resistance box.