Helical coils can be used on___________?
(A) low voltage side of high kVA transformers
(B) high frequency transformers
(C) high voltage side of small capacity transformers
(D) high voltage side of high kVA rating transformers
The function of conservator in a transformer is___________________?
(A) to project against’internal fault
(B) to reduce copper as well as core losses
(C) to cool the transformer oil
(D) to take care of the expansion and contraction of transformer oil due to variation of temperature of sur-roundings
The thickness of laminations used in a transformer is usually____________?
(A) 0.4 mm to 0.5 mm
(B) 4 mm to 5 mm
(C) 14 mm to 15 mm
(D) 25 mm to 40 mm
Material used for construction of transformer core is usually___________________?
(A) wood
(B) copper
(C) aluminium
(D) silicon steel
Hysteresis loss in a transformer varies as CBmax = maximum flux density) ?
(A) Bmax
(B) Bmax1-6
(C) Bmax1-83
(D) B max
The noise resulting from vibrations of laminations set by magnetic forces, is termed as_________________?
(A) magnetostrication
(B) boo
(C) hum
(D) zoom
The transformer ratings are usually expressed in terms of______________?
(A) volts
(B) amperes
(C) kW
(D) kVA
The chemical used in breather is_______________?
(A) asbestos fiber
(B) silica sand
(C) sodium chloride
(D) silica gel
The chemical used in breather for transformer should have the quality of____________?
(A) ionizing air
(B) absorbing moisture
(C) cleansing the transformer oil
(D) cooling the transformer oil
Distribution transformers are generally designed for maximum efficiency around________________?
(A) 90% load
(B) zero load
(C) 25% load
(D) 50% load