Acts as a brake to the disc when the load is OFF

It helps the disc to move when load is ON

It reduces the friction error

It gives path for the magnetic flux

Creeping error

Speed error

Phase error

Friction error

10

8

7

6

90 Degree

120 Degree

180 Degree

360 Degree

Self induction

Mutual induction

Fall in potential

Lenzs law