A ferrite core has less eddy current loss than an iron core because_______________?

Related Mcqs:

1. In a magnetic material hysteresis loss takes place primarily due to___________?

   A. rapid reversals of its magnetisation
   B. flux density lagging behind magnetising force
   C. molecular friction
   D. it high retentivity

2. Those magnetic materials are best suited for making armature and transformer cores which have ________ permeability and ________ hystersis loss

   A. high, high
   B. low, high
   C. high, low
   D. low, low

3. Hysteresis loss least depends on____________?

   A. volume of material
   B. frequency
   C. steinmetz coefficient of material
   D. ambient temperature

4. If the area of hysteresis loop of a material is large, the hysteresis loss in this material will be____________?

   A. zero
   B. small
   C. large
   D. none of the above

5. Energy stored by a coil is doubled when its current is increased by percent___________?

   A. 25
   B. 50
   C. 41.4
   D. 100

6. The rate of rise of current through an inductive coil is maximum_____________?

   A. at 63.2% of its maximum steady value
   B. at the start of the current flow
   C. after one time constant
   D. near the final maximum value of current

7. The initial rate of rise of current through a coil of inductance 10 H when suddenly connected to a D.C. supply of 200 V is__________Vs

   A. 50
   B. 20
   C. 0.05
   D. 500

8. 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

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

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

10. Permanent magnets are normally made of_____________?

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