Electrical Machines

ELECTRICAL MACHINES Duration:30 min 1.What is the limiting temperature for naval division A insulation? (A)120C(B)130C(C)155C(D)105C autonomic nervous remains:D 2. The materials in army of decreasing eddy authorized firing willing be (A) iron, woodland, aluminium (B) iron, aluminium, wood (C) aluminium, iron, wood (D) wood, aluminium, iron. autonomic nervous system:C 3. sometimes a reactor is connected in series with a transformer to (A) assort regulation (B) control fault current (C) improve energy (D) improve power factor. autonomic nervous system:B 4. Which spill occurs in the yoke of a DC machine ? (A) iron loss(B) hair loss (C) heat loss(D) no loss. Ans:D 5.Skewing in the slots of an inductance repel is provided to centralise (A) iron loss (B) noise(C) harmonics (D) temperature rise. Ans:C 6. Inter poles in DC machines are provided to reduce (A) sparking (B) armature response (C) iron loss(D) efficiency. Ans:A 7. A catch decease is produced in a synchronous motor when (A) shipment fluctuates (B) release frequency varies (C) both (A) and (B) above (D) no(prenominal) of the above. Ans:C 8. In a synchronous generator in order to eliminate the 5th harmonic the chording angle should be (A) 9° (B) 18° (C) 27° (D) 36°. Ans:D 9.

Stampings in transformers are provided to reduce (A) hysteresis loss (B) eddy current loss(C) bull loss (D) completely of the above Ans:B 10. The losses occurring in the rotor of an induction motor are slight than those in the stator because of (A) small diameter of rotor (B) less (prenominal) rotor frequency (C) slot skew! ing (D) none of the above. Ans:B 11. The transformer noise is mainly because of (A) cooling oil (B) sinusoidal current(C) charismatic flux(D) all of the above Ans:C 12. For the uniform rating, the follow of an induction motor as compared to that of a DC motor is (A) more(B) less (C) same (D) nearly the same. Ans:B 13. In most AC machines, it is usually a mensuration practice to use (A) fractional slot winding With...If you want to dismay a full essay, order it on our website: BestEssayCheap.com

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