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EEE :: Magnetic Circuit

  1. The relative permeability of a ferromagnetic material is

  2. A.

     Less than one

    B.

     More than one

    C.

     More than 10

    D.

     More than 100 Ωr 1000


  3. Energy stored by a coil is doubled when its current is increased by percent.

  4. A.

     25

    B.

     50.14

    C.

     41.4

    D.

     100


  5. Hard steel is suitable for making permanent magnets because

  6. 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


  7. The unit of reluctance is

  8. A.

     Meter/Henry

    B.

     Henry/meter

    C.

     Henry

    D.

     1/Henry


  9. Hysteresis loss least depends on

  10. A.

     Volume of material

    B.

     Frequency

    C.

     Steinmetz’s coefficient of material

    D.

     Ambient temperature


  11. The rate of rise of current through an inductive coil is maximum

  12. 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


  13. The property of a material which opposes the creation of magnetic flux in it is known as

  14. A.

     Reluctivity

    B.

     Magneto-motive force

    C.

     Permeance

    D.

     Reluctance


  15. Conductivity is analogous to

  16. A.

     Retentivity

    B.

     Resistivity

    C.

     Permeability

    D.

     Inductance