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
Related Mcqs:
- 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 - Energy stored by a coil is doubled when its current is increased by percent___________?
A. 25
B. 50
C. 41.4
D. 100 - 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 - 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 - 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 - 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 - Conductance is analogous to_____________?
A. permeance
B. reluctance
C. flux
D. inductance - Silicon steel is used in electrical machines because it has_____________?
A. low coercivity
B. low retentivity
C. low hysteresis loss
D. high coercivity - 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 - A material for good magnetic memory should have____________?
A. low hysteresis loss
B. high permeability
C. low retentivity
D. high retentivity
