Design of Electrical Machines Mock Test 5

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Question 1 of 10

1. What is the pulsational force produced for 500 MW machine?

80 kN per m

90 kN per m

60 kN per m

70 kN per m

Question 1 of 10

Question 2 of 10

2. What is the range of the leakage coefficient in the pole body?

1.00 to 1.5

1.15 to 1.2

0.75 to 2.3

1.1 to 1.2

Question 2 of 10

Question 3 of 10

3. The field winding should be designed for a voltage from 15-20% less than the exciter voltage.

false

true

Question 3 of 10

Question 4 of 10

4. How many factors does the construction of the turbo alternators depend upon?

Question 4 of 10

Question 5 of 10

5. How is the number of armature slots associated with the flux densities in iron?

tooth ripples are decreased, if the number of slots are increased

tooth ripples are increased, if the number of slots are decreased

tooth ripples are increased, if the number of slots are increased

tooth ripples are decreased, if the number of slots are decreased

Question 5 of 10

Question 6 of 10

6. What is the range of the pole face loss in the synchronous machines?

40-60 % of iron loss

40-80 % of iron loss

25-70 % of iron loss

20-60 % of iron loss

Question 6 of 10

Question 7 of 10

7. What is the formula for the cooling co-efficient to the rotating field coils?

cooling coefficient of rotating field coils = 0.05 to 0.08 / 1 - armature voltage

cooling coefficient of rotating field coils = 0.08 to 0.12 / 1 - armature voltage

cooling coefficient of rotating field coils = 0.05 to 0.08 / 1 + armature voltage

cooling coefficient of rotating field coils = 0.08 to 0.12 / 1 + armature voltage

Question 7 of 10

Question 8 of 10

8. What is the permissible current density in the armature conductors?

3-4 A per mm²

3-5 A per mm²

4-6 A per mm²

3-6 A per mm²

Question 8 of 10

Question 9 of 10

9. How many layers does the machine with Class F insulation consists of?

Question 9 of 10

Question 10 of 10

10. How is the number of armature slots associated with the armature windings?

number of slots should be such that unbalanced winding is obtained

number of slots should be so low as possible

number of slots should be such that balanced winding is obtained

number of slots should be high as possible

Question 10 of 10