A. The current in the slot conductors is uniformly distributed over their cross-section
B. The leakage path is straight across the slot and around the iron at the bottom
C. The permanence of air paths is only considered. The reluctance of iron paths is assumed as zero
D. All of the above
Related Mcqs:
- In D.C. machines the usual limit of slot pitch is________________?
A. between 5 to 10 mm
B. between 10 to 15 mm
C. between 15 to 20 mm
D. between 25 to 35 mm - Which of the following is the major consideration to evolve a good design ?
A. Cost
B. Durability
C. Compliance with performance criteria as laid down in specifications
D. All of the above - Which of the following materials is used in the manufacture of resistance grids to be used in the starters of large motors ?
A. Copper
B. Aluminium
C. Steel
D. Cast-iron - The heated parts of an electrical machine dissipate heat into their surroundings by which of the following modes of heat dissipation ?
A. Conduction
B. Convection
C. Radiation
D. All of the above - On which of the following variables heat convected depends ?
A. Power density
B. Temperature difference between heated surface and coolant
C. Thermal resistivity, density, specific heat
D. Gravitational constant
E. All of the above - By which of the following methods motor rating for variable load drives can be determined ?
A. Method of average losses
B. Equivalent current method
C. Equivalent torque method
D. Equivalent power method
E. All of the above - Which of the following methods may be adopted to reduce the effects of armature reaction ?
A. Increase in length of air gap at pole tips
B. Increasing reluctance of pole tips
C. Compensating windings
D. Interpoles
E. All of the above - For large power transformers, self oil cooled type or air blast type which of the following values of current density may be used?
A. 1.0 to 1.2 A/mm2
B. 1.5 to 2.0 A/mm2
C. 2.2 to 3.2 A/mm2
D. 3.2 to 4.2 A/mm2 - The heat dissipating capability of transformers of ratings higher than 30 kVA in increased by providing which of the following ?
A. Corrugations
B. Fins
C. Tubes
D. Radiator tanks
E. All of the above - For 275 kV transformers, using cold rolled grain oriented steel, which of the following values of flux density may be used?
A. 1.0 Wb/m2
B. 1.1 Wb/m2
C. 1.3 Wb/m2
D. 1.6 Wb/m2
E. None of the above
