Iron
Silicon steel
High carbon steel
Stainless steel
The motor pickup very high speed
The motor will slow down
The motor will stop
The motor will run normally
DC compound
DC shunt
DC series
DC long shunt compound
By changing the polarity of supply terminal
By changing the terminal of series field
By interchanging brush contact position
By changing the terminals of the armature
Increasing field current
Decreasing field current
Increasing armature current
Decreasing armature current