Design of Electrical Machines Mock Test 7

10%

Question 1 of 10

1. To reduce the peak voltage between layers, the secondary winding is being sectionalized.

true

false

Question 1 of 10

Question 2 of 10

2. The current transformers are assembled on to the secondary conductors “on site” for either permanent or temporary duty.

false

true

Question 2 of 10

Question 3 of 10

3. What is the relation of the secondary winding leakage reactance and secondary circuit impedance?

secondary winding leakage reactance is indirectly proportional to the square of the secondary circuit impedance

secondary winding leakage reactance is directly proportional to the secondary circuit impedance

secondary winding leakage reactance is directly proportional to the square of the secondary circuit impedance

secondary winding leakage reactance is indirectly proportional to the secondary circuit impedance

Question 3 of 10

Question 4 of 10

4. What is the best number of secondary turns of the current transformer?

1 or 2 more than the number such that the turns ratio is equal to the nominal current ratio

1 or 2 less than the number such that the turns ratio is equal to the nominal current ratio

Question 4 of 10

Question 5 of 10

5. What is the value of the resistivity temperature coefficient of copper?

0.0173 ohm per m per mm²

0.017 ohm per m per mm²

0.0175 ohm per m per mm²

0.01734 ohm per m per mm²

Question 5 of 10

Question 6 of 10

6. How many types are the current transformers classified into?

Question 6 of 10

Question 7 of 10

7. What is the maximum value above which the total width of the bands should not exceed?

30-35% of the axial length of armature core

25-35% of the axial length of armature core

25-30% of the axial length of armature core

35-40% of the axial length of armature core

Question 7 of 10

Question 8 of 10

8. What is the second property of the shaft design?

the shaft design should be such that it should have high corrosion resistance

the shaft design should be such that it should withstand voltage fluctuations

the shaft design should be such that it should have high tensile strength

the shaft design should be such that it has high rigidity

Question 8 of 10

Question 9 of 10

9. In what machines are the wire bands along the active length of windings placed?

dc or ac machines

dc machines

ac machines

dc and ac machines

Question 9 of 10

Question 10 of 10

10. What is the formula for the outer cylindrical heat dissipating surface of the magnet coils?

outer cylindrical heat dissipating surface = 3.14 + outer diameter of coil + axial length of coil

outer cylindrical heat dissipating surface = 3.14 * outer diameter of coil * axial length of coil

outer cylindrical heat dissipating surface = 3.14 / outer diameter of coil + axial length of coil

outer cylindrical heat dissipating surface = 3.14 * outer diameter of coil + axial length of coil

Question 10 of 10