DC MOTOR - Practice Mode

1) How to obtain opposite polarity in adjacent poles of a 4 pole DC motor?
Correct Answer: Making current flow in different direction
2) Which insulating material used in winding is a highly non -hygroscopic and possess good electrical strength?
Correct Answer: Millinex paper
3) Calculate the average pitch (YA) for retrogressive wave winding, if No. of armature conductor = 14 No. of slots = 7 No. of poles = 2
Correct Answer: 6
4) Why the newly rewound armature must be preheated before varnishing?
Correct Answer: Drive out the moisture from it
5) How the direction of rotation of a DC compound motor is changed?
Correct Answer: By changing the direction of armature current