A. Induction
B. Interaction
C. Alignment
D. All of the above
0
The change in flux linkages can be caused in which of the following ways ?
0
Commercial available medium size machines have a speed range of __________ ?
A. The flux is constant with respect to time and is stationary and the coil moves through it
B. The coil is stationary with respect to flux and the flux varies in magnitude with respect to time
C. Both the changes mentioned above occur together, i.e., the coil moves through a time varying field
D. All of the above
0
__________ has a low relative permeability and is used principally in field frames when cost is of primary importance and extra weight is not objectionable?
A. 200 to 400 r.p.m
B. 600 to 1000 r.p.m
C. 1000 to 1500 r.p.m
D. 2000 to 2500 r.p.m
0
_______________is universally used for windings of electrical machines because it is easily workable without any possibility of fracture?
A. Cast steel
B. Aluminium
C. Soft steel
D. Cast iron
0
Materials exhibiting zero value of resistivity are known as ____________ ?
A. Silver
B. Steel
C. Aluminium
D. Copper
0
Hot rolled sheets have ___________ value of permeability?
A. conductors
B. semiconductors
C. insulators
D. superconductors
0
Aluminium when adopted as a conductor material in __________ transformers, decreases the overall cost of the transformer?
A. zero
B. low
C. high
D. none of the above
0
__________is extensively used for those portions of magnetic circuit which carry steady flux and need superior mechanical properties ?
A. small size
B. medium size
C. large size
D. any of the above size
0
The heat dissipated by from a surface depends upon its temperature and its characteristics like colour, roughness etc?
A. Grey cast-iron
B. Cast steel
C. High carbon steel
D. Stainless steel
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