Electrical Machine Design MCQs

Option A: Cost

Option B: Durability

Option C: Compliance with performance criteria as laid down in specifications

Option D: All of the above

Correct Answer: All of the above ✔

Option A: equal to

Option B: less than

Option C: more than

Option D: none of the above

Correct Answer: more than ✔

Option A: minimum

Option B: maximum

Option C: nil

Option D: none of the above

Correct Answer: maximum ✔

Option A: single layered

Option B: double layered

Option C: multi-layered

Option D: none of the above

Correct Answer: multi-layered ✔

Option A: upto 20 kV

Option B: upto 50 kV

Option C: upto 80 kV

Option D: for 110 kV and above

Correct Answer: for 110 kV and above ✔

Option A: minimum

Option B: maximum

Option C: nil

Option D: none of the above

Correct Answer: maximum ✔

Option A: distribution transformers

Option B: power transformers

Option C: shell type transformers

Option D: none of the above

Correct Answer: power transformers ✔

Option A: short capacity transformers

Option B: medium capacity transformers

Option C: high capacity transformers

Option D: any of the above

Correct Answer: high capacity transformers ✔

Option A: upto 5 MVA

Option B: upto 10 MVA

Option C: upto 20 MVA

Option D: 30 MVA upwards

Correct Answer: 30 MVA upwards ✔

Option A: Corrugations

Option B: Fins

Option C: Tubes

Option D: Radiator tanks

Correct Answer: All of the above ✔

Option A: 2 MVA

Option B: 5 MVA

Option C: 7.5 MVA

Option D: 10 MVA

Correct Answer: 10 MVA ✔

Option A: Adjustment of voltage at consumers premises within statutory limits

Option B: Control of active and reactive power

Option C: Adjustment of short period daily and seasonal voltage variations in accordance with variations of load

Option D: All of the above

Correct Answer: All of the above ✔

Option A: Electrical considerations

Option B: Mechanical considerations

Option C: Thermal considerations

Option D: All of the above

Correct Answer: All of the above ✔

Option A: 1.5 to 2.5 A/mm2

Option B: 3.5 to 4.5 A/mm2

Option C: 4.0 to 5.0 A/mm2

Option D: 5.4 to 6.2 A/mm2

Correct Answer: 5.4 to 6.2 A/mm2 ✔

Option A: 1.0 Wb/m2

Option B: 1.1 Wb/m2

Option C: 1.3 Wb/m2

Option D: 1.6 Wb/m2

Correct Answer: 1.6 Wb/m2 ✔

Option A: sometimes 2-layer type

Option B: never 2-layer type

Option C: always 2-layer type

Option D: none of the above

Correct Answer: always 2-layer type ✔

Option A: Cylindrical winding with circular conductors

Option B: Cross-over winding with either circular or small rectangular conductors

Option C: Continuous disc type winding with rectangular conductors

Option D: All of the above types

Correct Answer: All of the above types ✔

Option A: 40°C

Option B: 60°C

Option C: 80°C

Option D: 104°C

Correct Answer: 104°C ✔

Option A: 0.5 to 0.8 Wb/m2

Option B: 0.8 to 1.0 Wb/m2

Option C: 1.1 to 1.35 Wb/m2

Option D: 1.4 to 1.8 Wb/m2

Correct Answer: 1.1 to 1.35 Wb/m2 ✔

Option A: 1.0 to 1.2 A/mm2

Option B: 1.5 to 2.0 A/mm2

Option C: 2.2 to 3.2 A/mm2

Option D: 3.2 to 4.2 A/mm2

Correct Answer: 2.2 to 3.2 A/mm2 ✔

Option A: 1 + 0.2 kVmm

Option B: 2 + 0.5 kVmm

Option C: 4 + 0.7 kV mm

Option D: 5 + 0.9 kV mm

Correct Answer: 5 + 0.9 kV mm ✔

Option A: low voltage transformers

Option B: medium voltage transformers

Option C: high voltage transformers

Option D: any of the above

Correct Answer: high voltage transformers ✔

Option A: minor insulation

Option B: major insulation

Option C: either of the above

Option D: none of the above

Correct Answer: major insulation ✔

Option A: Radial

Option B: Trailing

Option C: Reaction

Option D: All of the above

Correct Answer: All of the above ✔

Option A: Natural graphite

Option B: Hard carbon

Option C: Electro graphitic

Option D: Metal graphite

Correct Answer: Natural graphite ✔

Option A: 0.1 to 0.2 mm

Option B: 0.2 to 0.3 mm

Option C: 0.3 to 0.4 mm

Option D: 0.4 to 0.5 mm

Correct Answer: 0.4 to 0.5 mm ✔

Option A: purely D.C. control systems

Option B: purely AC. control systems

Option C: both D.C. and AC. control systems

Option D: none of the above

Correct Answer: A. purely D.C. control systems ✔

Option A: upto 20 A

Option B: upto 40 A

Option C: upto 60 A

Option D: upto 80 A

Correct Answer: upto 80 A ✔

Option A: Traction

Option B: Drives for process industry

Option C: Battery driven vehicles

Option D: Automatic control

Correct Answer: All of the above ✔

Option A: main poles

Option B: interpoles

Option C: frame

Option D: all of the above

Correct Answer: all of the above ✔

Option A: Mild steel

Option B: Copper

Option C: Aluminium

Option D: Cast-iron

Correct Answer: Cast-iron ✔

Option A: Metal graphite brushes

Option B: Hard carbon brushes

Option C: Electro-graphitic brushes

Option D: Natural graphite brushes

Correct Answer: Metal graphite brushes ✔

Option A: Increased I R losses

Option B: Increased core losses

Option C: Poor commutation

Option D: Change in motor parameters

Correct Answer: All of the above ✔

Option A: less than

Option B: equal to

Option C: greater than

Option D: none of the above

Correct Answer: equal to ✔

Option A: worst, ventilation

Option B: poor ventilation

Option C: better ventilation

Option D: none of the above

Correct Answer: better ventilation ✔

Option A: between 5 to 10 mm

Option B: between 10 to 15 mm

Option C: between 15 to 20 mm

Option D: between 25 to 35 mm

Correct Answer: between 25 to 35 mm ✔

Option A: quiet

Option B: noisy

Option C: either of the above

Option D: none of the above

Correct Answer: quiet ✔

Option A: equal to that of armature mmf

Option B: less in comparison with the armature mmf

Option C: large in comparison with the armature mmf

Option D: none of the above

Correct Answer: large in comparison with the armature mmf ✔

Option A: 10 m/s

Option B: 20 m/s

Option C: 30 m/s

Option D: 40 m/s

Correct Answer: 30 m/s ✔

Option A: increase

Option B: decrease

Option C: either of the above

Option D: none of the above

Correct Answer: increase ✔

Option A: 100 A

Option B: 200 A

Option C: 300 A

Option D: 400 A

Correct Answer: 400 A ✔

Option A: 4 mm

Option B: 6 mm

Option C: 8 mm

Option D: 10 mm

Correct Answer: 10 mm ✔

Option A: increase

Option B: decrease

Option C: either of the above

Option D: none of the above

Correct Answer: increase ✔

Option A: Increase in length of air gap at pole tips

Option B: Increasing reluctance of pole tips

Option C: Compensating windings

Option D: Interpoles

Correct Answer: All of the above ✔

Option A: between 2 to 4

Option B: between 6 to 8

Option C: between 9 to 16

Option D: between 20 to 30

Correct Answer: between 9 to 16 ✔

Option A: 5 percent

Option B: 10 percent

Option C: 15 percent

Option D: 30 percent

Correct Answer: 5 percent ✔

Option A: equal to 50 kVA

Option B: equal to 100 kVA

Option C: above 200 kVA

Option D: none of the above

Correct Answer: above 200 kVA ✔

Option A: Closed windings

Option B: Open windings

Option C: Either of the above

Option D: None of the above

Correct Answer: Closed windings ✔

Option A: duplex winding

Option B: triplex winding

Option C: forced winding

Option D: none of the above

Correct Answer: forced winding ✔

Option A: short pitch

Option B: full pitch

Option C: either of the above

Option D: none of the above

Correct Answer: full pitch ✔

Option A: front pitch

Option B: winding pitch

Option C: commutator pitch

Option D: back pitch

Correct Answer: winding pitch ✔

Option A: small machines

Option B: large machines

Option C: either A. or B.

Option D: none of the above

Correct Answer: large machines ✔

Option A: at one-fourth load

Option B: at one-half load

Option C: at or near full load

Option D: any of the above

Correct Answer: at or near full load ✔

Option A: small capacity transformers

Option B: medium capacity transformers

Option C: large capacity transformers

Option D: any of the above

Correct Answer: small capacity transformers ✔

Option A: Equivalent current method

Option B: Equivalent power method

Option C: Equivalent torque method

Option D: Method of average losses

Correct Answer: Equivalent current method ✔

Option A: Soft magnetic materials

Option B: Hard magnetic materials

Option C: Either A. or B.

Option D: None of the above

Correct Answer: Soft magnetic materials ✔

Option A: a.c. supply

Option B: d.c. supply

Option C: either a.c. or d.c. supply

Option D: none of the above

Correct Answer: C. either a.c. or d.c. supply
D. none of the above ✔

Option A: Flat-faced armature type

Option B: Horse shoe type

Option C: Flat-faced plunger type

Option D: All of the above

Correct Answer: All of the above ✔

Option A: Force equation

Option B: Magnetic circuit equation

Option C: Heating equation

Option D: Voltage equation

Correct Answer: All of the above ✔

Option A: Tractive

Option B: Portative

Option C: Either of the above

Option D: None of the above

Correct Answer: Portative ✔

Option A: Method of average losses

Option B: Equivalent current method

Option C: Equivalent torque method

Option D: Equivalent power method

Correct Answer: All of the above ✔

Option A: Total m.m.f. required

Option B: The number of turns in the exciting winding

Option C: The way in which the winding is distributed

Option D: All of the above

Correct Answer: All of the above ✔

Option A: Thermometer method

Option B: Resistance method

Option C: Embedded temperature detector method

Option D: Any of the above

Correct Answer: Any of the above ✔

Option A: One sided axial ventilation

Option B: Two sided axial ventilation

Option C: Multiple inlet system

Option D: All of the above

Correct Answer: All of the above ✔

Option A: The current in the slot conductors is uniformly distributed over their cross-section

Option B: The leakage path is straight across the slot and around the iron at the bottom

Option C: The permanence of air paths is only considered. The reluctance of iron paths is assumed as zero

Option D: All of the above

Correct Answer: All of the above ✔

Option A: Equivalent power method

Option B: Equivalent current method

Option C: Method of average losses

Option D: Equivalent torque method

Correct Answer: Method of average losses ✔

Option A: heating time constant

Option B: cooling time constant

Option C: either A. or B.

Option D: none of the above

Correct Answer: heating time constant ✔

Option A: 200 MW

Option B: 300 MW

Option C: 400 MW

Option D: 600 MW

Correct Answer: 600 MW ✔

Option A: 2 to 3 times greater

Option B: 3 to 4 times greater

Option C: 4 to 5 times greater

Option D: none of the above

Correct Answer: 2 to 3 times greater ✔

Option A: no mechanical difficulties

Option B: lesser mechanical difficulties

Option C: greater mechanical difficulties

Option D: none of the above

Correct Answer: greater mechanical difficulties ✔

Option A: solid

Option B: hollow

Option C: perforated

Option D: any ofthe above

Correct Answer: hollow ✔

Option A: 10 Q m

Option B: 100 Q m

Option C: 1000 Q m

Option D: 2000 Q m

Correct Answer: 2000 Q m ✔

Option A: “supercharged”

Option B: “inner cooled”

Option C: “conductor cooled”

Option D: any of the above

Correct Answer: any of the above ✔

Option A: 0.07

Option B: 1.5

Option C: 2.5

Option D: 3.5

Correct Answer: 0.07 ✔

Option A: Increase in efficiency

Option B: Increase in ratings

Option C: Increase in life

Option D: Smaller size of coolers

Correct Answer: All of the above ✔

Option A: Conduction

Option B: Convection

Option C: Radiation

Option D: All of the above

Correct Answer: All of the above ✔

Option A: air

Option B: hydrogen

Option C: either A. or B.

Option D: none of the above

Correct Answer: hydrogen ✔

Option A: 2

Option B: 3

Option C: 5

Option D: 7

Correct Answer: 7 ✔

Option A: Direct

Option B: Indirect

Option C: Conventional

Option D: Any of the above

Correct Answer: Direct ✔

Option A: 50 MW

Option B: 100 MW

Option C: 200 MW

Option D: none of the above

Correct Answer: 200 MW ✔

Option A: 1.5

Option B: 2.5

Option C: 3.5

Option D: 4.5

Correct Answer: 1.5 ✔

Option A: 10 MW

Option B: 30 MW

Option C: 60 MW

Option D: 150 MW

Correct Answer: 60 MW ✔

Option A: conduction

Option B: convection

Option C: radiation

Option D: any ofthe above

Correct Answer: convection ✔

Option A: Power density

Option B: Temperature difference between heated surface and coolant

Option C: Thermal resistivity, density, specific heat

Option D: Gravitational constant

Correct Answer: All of the above ✔

Option A: Copper

Option B: Aluminium

Option C: Steel

Option D: Cast-iron

Correct Answer: Cast-iron ✔

Option A: conduction

Option B: convection

Option C: radiation

Option D: any of the above

Correct Answer: radiation ✔

Option A: Grey cast-iron

Option B: Cast steel

Option C: High carbon steel

Option D: Stainless steel

Correct Answer: Cast steel ✔

Option A: small size

Option B: medium size

Option C: large size

Option D: any of the above size

Correct Answer: small size ✔

Option A: zero

Option B: low

Option C: high

Option D: none of the above

Correct Answer: low ✔

Option A: conductors

Option B: semiconductors

Option C: insulators

Option D: superconductors

Correct Answer: conductors ✔

Option A: Silver

Option B: Steel

Option C: Aluminium

Option D: Copper

Correct Answer: Copper ✔

Option A: Cast steel

Option B: Aluminium

Option C: Soft steel

Option D: Cast iron

Correct Answer: Cast iron ✔

Option A: 200 to 400 r.p.m

Option B: 600 to 1000 r.p.m

Option C: 1000 to 1500 r.p.m

Option D: 2000 to 2500 r.p.m

Correct Answer: 2000 to 2500 r.p.m ✔

Option A: The flux is constant with respect to time and is stationary and the coil moves through it

Option B: The coil is stationary with respect to flux and the flux varies in magnitude with respect to time

Option C: Both the changes mentioned above occur together, i.e., the coil moves through a time varying field

Option D: All of the above

Correct Answer: All of the above ✔

Option A: Induction

Option B: Interaction

Option C: Alignment

Option D: All of the above

Correct Answer: All of the above ✔

Option A: d.c. series motor .

Option B: d.c. shunt motor

Option C: induction motor

Option D: synchronous motor

Correct Answer: induction motor ✔

Option A: low

Option B: medium

Option C: high

Option D: any of the above

Correct Answer: high ✔

Option A: Saturation

Option B: Temperature rise

Option C: Efficiency

Option D: Power factor

Correct Answer: All above ✔

Option A: drastically increased

Option B: drastically reduced

Option C: unaffected

Option D: none of the above

Correct Answer: drastically reduced ✔

Option A: small size

Option B: medium size

Option C: large size

Option D: any of the above

Correct Answer: small size ✔