Silicon steel used in lamination’s mainly reduces___________?

Related Mcqs:

1. The degree of mechanical vibrations produced by the laminations of a transformer depends on____________?

   A. tightness of clamping
   B. gauge of laminations
   C. size of laminations
   D. all of the above

2. The thickness of laminations used in a transformer is usually____________?

   A. 0.4 mm to 0.5 mm
   B. 4 mm to 5 mm
   C. 14 mm to 15 mm
   D. 25 mm to 40 mm

3. The noise resulting from vibrations of laminations set by magnetic forces, is termed as_________________?

   A. magnetostrication
   B. boo
   C. hum
   D. zoom

4. The hum in a transformer is mainly attributed to______________?

   A. load changes
   B. oil in the transformer
   C. magnetostriction
   D. mechanical vibrations

5. The permissible flux density in case of cold rolled grain oriented steel is around__________?

   A. 1.7 Wb/m2
   B. 2.7 Wb/m2
   C. 3.7 Wb/m2
   D. 4.7 Wb/m2

6. A transformer core is laminated to__________?

   A. reduce hysteresis loss
   B. reduce eddy current losses
   C. reduce copper losses
   D. reduce all above losses

7. In a given transformer for given applied voltage, losses which remain constant irrespective of load changes are______________?

   A. friction and windage losses
   B. copper losses
   C. hysteresis and eddy current losses
   D. none of the above

8. A Buchholz relay can be installed on______________?

   A Buchholz relay can be installed on
   A. auto-transformers
   B. air-cooled transformers
   C. welding transformers
   D. oil cooled transformers

9. Which of the following loss in a transformer is zero even at full load ____________?

   A. Core loss
   B. Friction loss
   C. Eddy current loss
   D. Hysteresis loss

10. Which of the following insulating materials can withstand the highest temperature safely ?

    A. Cellulose
    B. Asbestos
    C. Mica
    D. Glass fibre