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
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 - 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 - Permeability in a magnetic circuit corresponds to________ in an electric circuit
A. resistance
B. resistivity
C. conductivity
D. conductance - The unit of retentivity is____________?
A. weber
B. weber/sq. m
C. ampere turn/meter
D. ampere turn - 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 - Reciprocal of reluctance is_______________?
A. reluctivity
B. permeance
C. permeability
D. susceptibility - 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 - The unit of magnetic flux is______________?
A. henry
B. weber
C. ampereturn/weber
D. ampere/metre - A material for good magnetic memory should have____________?
A. low hysteresis loss
B. high permeability
C. low retentivity
D. high retentivity
