In transformers using hot rolled steel, the cross-section of the yoke is made about __________ greater than that of the core?

Related Mcqs:

1. The usual values of maximum flux densities for distribution transformers using hot rolled silicon steel are______________?

   A. 0.5 to 0.8 Wb/m2
   B. 0.8 to 1.0 Wb/m2
   C. 1.1 to 1.35 Wb/m2
   D. 1.4 to 1.8 Wb/m2

2. 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

3. Hot rolled sheets have ___________ value of permeability?

   A. zero
   B. low
   C. high
   D. none of the above

4. The cold rolled grain oriented steel has ___________ permeability in the direction of the grain orientation?

   A. minimum
   B. maximum
   C. nil
   D. none of the above

5. The cold rolled grain oriented steel has _________ permeability in the direction of the grain orientation?

   A. minimum
   B. maximum
   C. nil
   D. none of the above

6. Aluminium when adopted as a conductor material in __________ transformers, decreases the overall cost of the transformer?

   A. small size
   B. medium size
   C. large size
   D. any of the above size

7. Transformers with a capacity of up to __________ have a cooling radiator system with natural cooling?

   A. 2 MVA
   B. 5 MVA
   C. 7.5 MVA
   D. 10 MVA

8. A current density of __________ is ilsed for large power transformers with forced circulation of oil or with water cooling coils?

   A. 1.5 to 2.5 A/mm2
   B. 3.5 to 4.5 A/mm2
   C. 4.0 to 5.0 A/mm2
   D. 5.4 to 6.2 A/mm2

9. Power transformers have rating_______________?

   A. equal to 50 kVA
   B. equal to 100 kVA
   C. above 200 kVA
   D. none of the above

10. Cylindrical windings using circular conductors, employed in transformers, are_____________?

    A. single layered
    B. double layered
    C. multi-layered
    D. none of the above