Significance: The restoring torque brings the coil back to its equilibrium (zero) position after the current is removed. It also provides a definite, measurable deflection for each current value, making the galvanometer a measuring instrument.

At equilibrium, deflecting torque = restoring torque:
$$nIAB = k\theta$$
$$\tau_{restoring} = k\theta$$
where:
- $k$ = torsional constant of the spring (N·m/rad)
- $\theta$ = angular deflection of the coil (rad)
- $n$ = number of turns, $I$ = current, $A$ = area, $B$ = magnetic field

This gives: $I = \left(\frac{k}{nAB}\right)\theta$ — current is proportional to deflection.