The unit of retentivity is____________?

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. The unit of reluctance is_____________?

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

3. The unit of magnetic flux is______________?

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

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

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

5. Relative permeability of vacuum is__________?

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

6. 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

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

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

8. Reciprocal of reluctance is_______________?

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

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. Permanent magnets are normally made of_____________?

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