92. A current density of __________ is ilsed for large power transformers with forced circulation of oil or with water cooling coils? A. 1.5 to 2.5 A/mm2 B. 3.5 to 4.5 A/mm2 C. 4.0 to 5.0 A/mm2 D. 5.4 to 6.2 A/mm2 Answer Discus (0) Answer & Solution Answer: D . 5.4 to 6.2 A/mm2 No Solution for this Answer..! Report or Discus this Question
93. Which of the following is the basic consideration in the design of insulation ? A. Electrical considerations B. Mechanical considerations C. Thermal considerations D. All of the above Answer Discus (0) Answer & Solution Answer: D . All of the above No Solution for this Answer..! Report or Discus this Question
94. The voltage control in electric supply networks in required on account of which of the following reasons ? A. Adjustment of voltage at consumers premises within statutory limits B. Control of active and reactive power C. Adjustment of short period daily and seasonal voltage variations in accordance with variations of load D. All of the above Answer Discus (0) Answer & Solution Answer: D . All of the above No Solution for this Answer..! Report or Discus this Question
95. Transformers with a capacity of up to __________ have a cooling radiator system with natural cooling? A. 2 MVA B. 5 MVA C. 7.5 MVA D. 10 MVA Answer Discus (0) Answer & Solution Answer: D . 10 MVA No Solution for this Answer..! Report or Discus this Question
96. The heat dissipating capability of transformers of ratings higher than 30 kVA in increased by providing which of the following ? A. Corrugations B. Fins C. Tubes D. Radiator tanks E. All of the above Answer Discus (0) Answer & Solution Answer: E . All of the above No Solution for this Answer..! Report or Discus this Question
97. The forced oil and air circulation method is usual one for transformers of capacities____________? A. Upto 5 MVA B. Upto 10 MVA C. Upto 20 MVA D. 30 MVA upwards Answer Discus (0) Answer & Solution Answer: D . 30 MVA upwards No Solution for this Answer..! Report or Discus this Question
98. Disc windings are primarily used in_____________-? A. Short capacity transformers B. Medium capacity transformers C. High capacity transformers D. Any of the above Answer Discus (0) Answer & Solution Answer: C . High capacity transformers No Solution for this Answer..! Report or Discus this Question
99. Helical windings are used in________________? A. Distribution transformers B. Power transformers C. Shell type transformers D. None of the above Answer Discus (0) Answer & Solution Answer: B . Power transformers No Solution for this Answer..! Report or Discus this Question
100. The cold rolled grain oriented steel has ___________ permeability in the direction of the grain orientation? A. Minimum B. Maximum C. Nil D. None of the above Answer Discus (0) Answer & Solution Answer: B . Maximum No Solution for this Answer..! Report or Discus this Question
101. Multi-layer helical windings are commonly used in the transformers as high voltage windings_______________? A. Upto 20 kV B. Upto 50 kV C. Upto 80 kV D. For 110 kV and above Answer Discus (0) Answer & Solution Answer: D . For 110 kV and above No Solution for this Answer..! Report or Discus this Question
102. Cylindrical windings using circular conductors, employed in transformers, are_____________? A. Single layered B. Double layered C. Multi-layered D. None of the above Answer Discus (0) Answer & Solution Answer: C . Multi-layered No Solution for this Answer..! Report or Discus this Question
103. The cold rolled grain oriented steel has _________ permeability in the direction of the grain orientation? A. Minimum B. Maximum C. Nil D. None of the above Answer Discus (0) Answer & Solution Answer: B . Maximum No Solution for this Answer..! Report or Discus this Question
104. The input impedance of a JFET is _____________that of an ordinary transistor? A. Equal to B. Less than C. More than D. None of the above Answer Discus (0) Answer & Solution Answer: C . More than No Solution for this Answer..! Report or Discus this Question
