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

Related Mcqs:

1. Those materials are well suited for making permanent magnets which have ________ retentivity and _________ coercivity

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

2. Permeability in a magnetic circuit corresponds to________ in an electric circuit

   A. resistance
   B. resistivity
   C. conductivity
   D. conductance

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

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

4. 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

5. 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

6. The relative permeability of a ferromagnetic material is_____________?

   A. less than one
   B. more than one
   C. more than 10
   D. more than 100 or 1000

7. Relative permeability of vacuum is__________?

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

8. The property of a material which opposes the creation of magnetic flux in it is known as_____________?

   A. reluctivity
   B. magnetomotive force
   C. permeance
   D. reluctance

9. 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

10. A material for good magnetic memory should have____________?

    A. low hysteresis loss
    B. high permeability
    C. low retentivity
    D. high retentivity