Design of Electrical Machine 2

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Electrical Engineering MCQ Question Papers: Campus Placement

Subject: Design of Electrical Machine 2

Part 2: List for questions and answers of Design of Electrical Machine

 

Q1. For simplex wave and lap windings, the back pitch yb and front pitch yf are as follows:

a) yb is odd, yf is even

b) yb is even, yfis odd

c) both yb and yf are odd

d) both yb and yf are even

 

Q2. All of the following are ferromagnetic materials EXCEPT

a) Nickel

b) Bismuth

c) Silicon

d) Mild steel

 

Q3. Diamagnetic: Copper:: Ferromagnetic:

a) Iron

b) Lead

c) Air

d) Water

 

Q4. Diamagnetic : Ferromagnetic ::

a) Copper: Silver

b) Air: Water

c) Iron: Steel

d) Lead: Cobalt

 

Q5. Which of the following gives materials in order of increasing values of permeability ?

a) Water, Iron. Copper, Silver

b) Water, Air, Pure iron. Permalloy

c) Cobalt, Aluminium, Copper, Silver

d) Silicon iron. Palladium, Lead, Silver

 

Q6. By adding silicon to ferromagnetic , materials

a) Electrical resistivity increases and also magnetic permeability increases

b) Electrical resistivity decreases and also magnetic permeability increases

c) Electrical resistivity decreases and magnetic permeability increases

d) Electrical resistivity increases and magnetic permeability decreases 

 

Q7. Which of the following can be worked with higher flux densities ?

a) Mild steel

b) Silicon iron

c) Cold rolled silicon steel

d) Hot rolled silicon steel

 

Q8. Hysteresis loss varies with frequency (f) as

a) f

b) f 1.6

c) f 2

d) f 2.6

 

Q9. Hysteresis loss varies with maximum flux density (B) as

a) B

b) B1.6

c) B2

d) B2.6

 

Q10. In large bulky materials, the uni-axial anisotropy can be induced by

a) Cold rolling

b) Magnetic annealing

c) Magnetic quenching

d) Any of the above

 

Q11. Magnetostriction

a) Grain oriented magnetic properties

b) Represents the upper limit to which magnetic properties can be induced

c) Change in dimensions resulting from magnetisation of ferromagnetic materials

d) None of the above

 

Q12. An ideal insulating material should have low

a) Insulation resistance

b) Dielectric strength

c) Dielectric loss angle

d) Mechanic strength

 

Q13. The class of insulation used for large rating HV alternators

a) Y

b) A

c) B

d) C 

 

Q14. Asbestos has

a) Fibrous structure

b) Crystalline structure

c) Grain oriented crystalline structure

d) None of the above

 

Q15. Asbestos can bear a temperature up to __________ without loosing its insulating properties

a) 100 degree C

b) 200 degree C

c) 300 degree C

d) 400 degree C

 

Q16. Fibre glass insulation can be used up to temperature of

a) 60 degree C

b) 80 degree C

c) 130 degree C

d) 180 degree C

 

Q17. Raw form of natural rubber is known as

a) Malamine

b) Milk of lime

c) Epoxy

d) Latex

 

Q18. Which of the following is the characteristic of ceramic insulators ?

a) These are hard, strong and dense

b) These are stable at high temperatures

c) These are unaffected by commercial acids and alkalies

d) All of the above

 

Q19. The number of commutator segments in a dc machine is equal to the no. of

a) Coil-sides

b) Turns

c) Coils

d) Slots 

 

Q20. Dielectric strength of PVC is around

a) 5 kV/mm

b) 10 kV/mm

c) 15 kV/mm

d) 30 kV/mm 

 

Part 2: List for questions and answers of Design of Electrical Machine

 

Q1. Answer: c

 

Q2. Answer: b

 

Q3. Answer: a

 

Q4. Answer: d

 

Q5. Answer: b

 

Q6. Answer: c

 

Q7. Answer: c

 

Q8. Answer: a

 

Q9. Answer: b

 

Q10. Answer: d

 

Q11. Answer: c

 

Q12. Answer: c

 

Q13. Answer: d

 

Q14. Answer: a

 

Q15. Answer: d

 

Q16. Answer: c

 

Q17. Answer: d

 

Q18. Answer: d

 

Q19. Answer: c

 

Q20. Answer: d