Specifications

QUESTIONS

Part - A

Choose the Correct Answer (1 Mark)

1. In double layer winding to ensure that all the coils have the same pitch and turns, there will

be ____________ coil side(s) in each slot

A) one B) four C) six D) two

2. One of the most important operations in winding an armature is to lace the coil leads in the

proper

A) commutator bar B) armature slot C) brushes D) poles

3. The size of the iron used for soldering depends on the size of the

A) brushes B) poles C) stator D) commutator

4. Small DC armature conductors are kept in the commutator raiser slits and spot welded.

This is called

A) brazing B) hot stacking C) banding D) soldering

5. To prevent the leads from flying out of the slots, while the armature is rotating, ________ is

used.

A) brazing B) soldering C) cord band D) lead swing

Part - B

Answer the following questions in one or two words (1 Mark)

1. Name the process which makes the coil moisture-roof and also prevents vibration of the

coils of wire in the slots.

2. Which has a tendency to impair the insulation on the wires and cause shorts?

3. Armatures should be tested for balancing after they are varnished. What is that balancing

called?

4. How are the resistance of the armature coils measured?

5. Name an electromagnetic device that is used to detect and locate grounded, shorted and

open coils in an armature.

Part - C

Answer the following questions briefly (4 Marks)

1. Explain the different methods of winding.

2. What is meant by hot stacking?

3. Why is the armature banded? Explain.

4. What is the need for balancing the armature?

5. What is meant by static balancing?

6. What is meant by dynamic balancing?

7. Why is an armature tested after winding?

8. What are the different methods of testing?

9. What is meant by insulation resistance test?

10. What is growler’s test? What are the different methods of growler’s test?

Part - D

Answer the following questions in two page level (20 Marks)

1. Explain with a neat sketch, the internal and external growler.

2. Explain the Growler test for A) a grounded coil and B) an open coil