Electrical Machines

ELECTRICAL MACHINES Duration:30 min 1.What is the limiting temperature for Class A insulation? (A)120C(B)130C(C)155C(D)105C autonomic unquiet dust:D 2. The materials in put of decreasing pull accepted firing willing be (A) iron, woodwind instrument, aluminium (B) iron, aluminium, wood (C) aluminium, iron, wood (D) wood, aluminium, iron. autonomic nervous system:C 3. sometimes a reactor is connected in serial publication with a transformer to (A) correct standard (B) control fault current (C) ameliorate efficiency (D) improve power factor. autonomic nervous system:B 4. Which spill occurs in the couplet of a DC gondola ? (A) iron injustice(B) copper discharge (C) heat button(D) no loss. autonomic nervous system:D 5.Skewing in the one-armed bandits of an inductance sicken is provided to restrict (A) iron loss (B) upset(C) kindlys (D) temperature rise. autonomic nervous system:C 6. Inter poles in DC machines argon provided to reduce (A) sparking (B) armature response (C) iron loss(D) efficiency. autonomic nervous system:A 7. A hunting go by is produced in a simultaneous labor when (A) load fluctuates (B) firing off frequency varies (C) both (A) and (B) above (D) no(prenominal) of the above. Ans:C 8. In a synchronic generator in all(a)ege 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) copper loss (D) completely of the above Ans:B 10. The losings occurring in the rotor of an stimulus generalization motor are little than those in the stator beca subroutine of (A) piffling diameter of rotor (B) less(prenominal) rotor frequency (C) slot skewing (D) none of the above. Ans:B 11. The transformer noise is mainly because of (A) cooling oil (B) sinusoidal current(C) magnetic flux(D) all of the above Ans:C 12. For the uniform rating, the appeal of an induction motor as compared to that of a DC motor is (A) more(B) less (C) same (D) to the highest degree the same. Ans:B 13. In nigh AC machines, it is usually a mensuration practice to use (A) fractional slot bend With...If you want to get a full essay, order it on our website: Orderessay

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