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Answer :

Dc machine is classified as 

  1.  self excited
  2.  separately excited
  3.  permanent magnet 

Self excited Dc motor is further classified as 

  1. series wound
  2. shunt wound
  3. compound wound

compound wound is further classified as

  1. cumulative compound
  2. differential compound
Each cumulative compound and differential compound  are classified as 

  1. long shunt
  2. short shunt
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