QUIZ2-EMD

Power transformers have rating

• equal to 50 kVA

• equal to 100 kVA

• above 200 kVA

• none of the above

The distance between the starts of two consecutive coils measured in terms of coil sides is called

• front pitch

• winding pitch

• commutator pitch

• back pitch

When the two coil sides forming a coil are spaced exactly one pole pitch apart they are said to be of

• short pitch

• full pitch

• either of the above

• none of the above

In induction motors, the length of air gap in kept as small as mechanically possible is order to have

• low power factor

• high power factor

• high over load capacity

• any of the above

Which of the following is the major consideration to evolve a good design ?

• Cost

• Durability

• Compliance with performance criteria as laid down in specifications

• All of the above

What are the parameters which come under the term “Main Dimensions”?

• diameter

• length

• diameter and length

• area

What is the range of the ratio of the core length to pole pitch for minimum cost?

• 1.5-2

• 1-2

• 1.0-1.25

• 2-2.5

What is the value of the ratio of the core length to pole pitch for good efficiency?

• 1

• 1.5

• 2

• 3

What is the relation between rotor mmf and stator mmf?

• rotor mmf = 0.85 * stator mmf

• rotor mmf = 0.80 * stator mmf

• rotor mmf = 0.75 * stator mmf

• rotor mmf = 0.70 * stator mmf

Closed slots are preferred for small machines.

• true

• false