Design of Electrical Machine 1

Electrical Engineering MCQ Question Papers: Campus Placement

Subject: Design of Electrical Machine 1

Part 1: List for questions and answers of Design of Electrical Machine

Q1. Which of the following gives materials in order of decreasing values of permeability ?

a) Cobalt, Nickel, Aluminium, Iron

b) Permalloy, Nickel, Air, Water

c) Silver, Copper, Aluminium, Iron

d) Pure iron, Silicon iron. Aluminium, Bismuth

Q2. In electrical machines the material preferred for pole shoes of electro-magnets is

a) Pure iron

b) Aluminium

c) Copper

Q3. The percentage of silicon in transformer stampings is usually limited to

a) 0.4%

b) 1.4%

c) 4%

d) 14%

Q4. Find the odd one out

a) Absorptivity

b) Emissivity

c) Refractive index

d) Dielectric strength

Q5. Diamagnetic : Paramagnetic::

a) Water: Air

b) Iron: Steel

c) Permalloy: Super-alloy

d) Nickel: Cobalt

Q6. If the permeability of a material is 0.999991. it can be classified as

a) Diamagnetic material

b) Paramagnetic material

c) Ferro-magnetic material

d) Ferrite

Q7. Which of the following material has the highest permeability ?

a) Nickel

b) Cobalt

c) Pure iron

d) Permalloy

Q8. For a simplex lap winding, the commutator pitch is equal to

a) +1

b) ±1

c) -l

d) ± 2

Q9. If the resistivity of aluminium is 0.0283 x 10^6m, the resistivity of copper could be

a) 0.017 x 10^5m

b) 0.0382 x 10^5m

c) 0.0832 x 10^6 m

d) 0.0889 x 10^6 m

Q10. Which variety of copper is used for overhead conductors ?

a) Hard drawn copper

b) Native copper

c) Annealed copper

d) Purest form of copper

Q11. Annealed copper is used in

a) low voltage cables

b) flexible wires

c) machine windings

d) all of the above

Q12. ACSR conductor has central core of steel surrounded by a bunch of aluminium wires. In such conductors

a) Current flows through aluminium conductors only

b) Current flows through steel wire only

c) Current flows through both steel as well as aluminium conductors

d) Majority of current flows through aluminium and negligible amount flows through steel

Q13. Which property of copper enables it to be drawn into thin wires and sheets ?

a) Ductility

b) Elasticity

c) Toughness

d) Tenacity

Q14. Which is non-magnetic material

a) Nickel

b) Cobalt

c) Aluminium

Q15. Which of the following is the least desired property in magnetic materials for electrical engineering applications ?

a) High magnetic permeability

b) High electrical resistivity

c) Large hysteresis loop

d) All of the above

Q16. Above Curie point

a) a ferromagnetic material becomes paramagnetic

b) a ferrite becomes an insulator

c) a insulating material becomes a ferrite

d) a diamagnetic material, becomes a paramagnetic material

Q17. For a simplex lap winding, the winding pitch is equal to

a) + 2

b) 2

c) ± 1

d) ± 2

Q18. If yb is the back pitch and u is the no. of coil sides per slot, then split coils can be avoided if the following quantity is an integer

a) (yb + 1)/ u

b) (yb + 1 )

c) (yb – 1)/ u

d) (yb – 1)

Q19. Which of the following is a paramagnetic material ?

c) Pure iron

d) All of the above

Q20. Which of the following is a ferromagnetic material ?

a) Pure iron

c) Bismuth

d) Water

Part 1: List for questions and answers of Design of Electrical Machine