Related Mcqs:

1. 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

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

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

3. When both the inductance and resistance of a coil are doubled the value of________________?

   A. time constant remains unchanged
   B. initial rate of rise of current is doubled
   C. final steady current is doubled
   D. time constant is halved

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

   A. ferrites have high resistance
   B. ferrites are magnetic
   C. ferrites have low permeability
   D. ferrites have high hysteresis

5. 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

6. 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

7. Conductance is analogous to_____________?

   A. permeance
   B. reluctance
   C. flux
   D. inductance

8. Silicon steel is used in electrical machines because it has_____________?

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

9. 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

10. A material for good magnetic memory should have____________?

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