Silicon steel is used in electrical machines because it has_____________?

Related Mcqs:

1. Laminated cores, in electrical machines, are used to reduce____________?

   A. copper loss
   B. eddy current loss
   C. hysteresis loss
   D. all of the above

2. Point out the wrong statement. Magnetic leakage is undesirable in electric machines because it___________?

   A. lowers their power efficiency
   B. increases their cost of manufacture
   C. leads to their increased weight
   D. produces fringing

3. While comparing magnetic and electric circuits, the flux of magnetic circuit is compared with which parameter of electrical circuit ?

   A. E.m.f.
   B. Current
   C. Current density
   D. Conductivity

4. Hard steel is suitable for making permanent magnets because_____________?

   A. it has good residual magnetism
   B. its hysteresis loop has large area
   C. its mechanical strength is high
   D. its mechanical strength is low

5. Relative permeability of vacuum is__________?

   A. 1
   B. 1 H/m
   C. 1/4JI
   D. 4n x 10-‘ H/m

6. The unit of retentivity is____________?

   A. weber
   B. weber/sq. m
   C. ampere turn/meter
   D. ampere turn

7. Reciprocal of reluctance is_______________?

   A. reluctivity
   B. permeance
   C. permeability
   D. susceptibility

8. The unit of reluctance is_____________?

   A. metre/henry
   B. henry/metre
   C. henry
   D. 1/henry

9. The unit of magnetic flux is______________?

   A. henry
   B. weber
   C. ampereturn/weber
   D. ampere/metre

10. Permanent magnets are normally made of_____________?

    A. alnico alloys
    B. aluminium
    C. cast iron
    D. wrought iron