A. 50
B. 20
C. 0.05
D. 500
Related Mcqs:
- 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 - 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 - Energy stored by a coil is doubled when its current is increased by percent___________?
A. 25
B. 50
C. 41.4
D. 100 - 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 - Conductivity is analogous to____________?
A. retentivity
B. resistivity
C. permeability
D. inductance - 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 - 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 - An air gap is usually inserted in magnetic circuits to____________?
A. increase m.m.f.
B. increase the flux
C. prevent saturation
D. none of the above - 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 - 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
