Consider the following statements : 1. interpole windings are connected in series with armature windings 2. polarity of interpoles must be the same as that of the main poles in advance 3. distortion of the main field under the pole shoes is not affected by the use of interpoles From above, the correct answer is

• A.  1 alone
• B.  2 and 3
• C.  1 and 3
• D.  1 and 2

Answer: (C)