Question

How is the jerky motion of the coil converted into smooth circular motion?

Answer 1

The jerky motion is converted into smooth circular motion by winding a number of coils of many turns on the same soft iron core, each coil being placed at a small angle to the next. When the deflecting couple tends to weaken in one coil, it becomes maximum in another coil. Thus, the resultant torque remains fairly steady and the rotation becomes smooth.