Design of Electrical Machines Questions and Answers – Pulsation Losses & Types of Leakages

This set of Design of Electrical Machines Multiple Choice Questions & Answers (MCQs) focuses on “Pulsation Losses & Types of Leakages”.

1. What happens in the rotating electrical machine?
a) armatures are slotted
b) armatures are slotted and results in the movement of rotor
c) the rotor remains stationary
d) the rotor slots are rotating
View Answer

2. What is pulsation losses?
a) flux pulsations are caused due to the slotted armature
b) flux pulsations are caused due to the rotation of machine
c) flux pulsation occurs due to rotor slots are rotating
d) flux pulsations occur due to the change in reluctance
View Answer

3. In which machine part/parts does the pulsation loss occurs?
a) teeth
b) pole face
c) conductors
d) teeth and pole faces
View Answer

4. How are the pulsation losses aggravated?
a) if the air gap is small compared with slot openings
b) if the air gap is reduced
c) if the air gap is increased
d) if the air gap is made larger than the slot openings
View Answer

5. The slotting produces harmonic fields which cause high frequency losses near the gap surface.
a) true
b) false
View Answer

6. In which machine is the pulsation losses considerable?
a) synchronous motors
b) induction motors
c) dc shunt motors
d) dc series motors
View Answer

7. What are the factors the permeance depends upon in the zigzag leakage?
a) relative position of stator
b) relative position of rotor
c) relative position of stator and rotor
d) stored energy at any position
View Answer

8. What is the formula for the stored energy at any position?
a) stored energy at any position = mmf per slot² * permeance in a particular position
b) stored energy at any position = 2 * mmf per slot² * permeance in a particular position
c) stored energy at any position = 1/2 * mmf per slot² * permeance in a particular position
d) stored energy at any position = 1/3 * mmf per slot² * permeance in a particular position
View Answer

9. What is the formula for the zigzag permeance?
a) zigzag permeance = average width of the rotor tooth / (1/2 * mmf per slot²)
b) zigzag permeance = average width of the rotor tooth * (1/2 * mmf per slot²)
c) zigzag permeance = 1/average width of the rotor tooth *(1/2 * mmf per slot²)
d) zigzag permeance = average width of the rotor tooth *(1/2 / mmf per slot²)
View Answer

10. What is the formula of the zigzag specific permeance?
a) zigzag specific permeance = average width of the rotor tooth * length / (1/2 * mmf per slot²)
b) zigzag specific permeance = average width of the rotor tooth / length * (1/2 * mmf per slot²)
c) zigzag specific permeance = average width of the rotor tooth * length * (1/2 * mmf per slot²)
d) zigzag specific permeance =1/ average width of the rotor tooth * length * (1/2 * mmf per slot²)
View Answer

11. What are the factors the overhang leakage reactance is obtained?
a) length of the overhang
b) diameter of the overhang
c) shape of the overhang
d) length of the overhang along with the shape of the overhang
View Answer

12. The overhang leakage reactance depends on the degree of saturation in the ferromagnetic parts.
a) true
b) false
View Answer

13. What is the relation between the overhang specific permeance and the slot pitch?
a) overhang specific permeance is directly proportional to the slot pitch
b) overhang specific permeance is indirectly proportional to the slot pitch
c) overhang specific permeance is directly proportional to the square of the slot pitch
d) overhang specific permeance is indirectly proportional to the square of the slot pitch
View Answer

Sanfoundry Global Education & Learning Series – Design of Electrical Machines.

To practice all areas of Design of Electrical Machines, here is complete set of 1000+ Multiple Choice Questions and Answers.

If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]