27, णः द tansformer the all day efficiency primarily depends on :
(ക) the amount of load (B) duration of load
(C) its copper loss (D) both (A) and (B)
28. If a D.C. motor is connected across the A.C. supply it will ;
(A) run at normal speed
(8) mnot run
(C) ரமா மண ‏٤٭د‎
‎(D) ण्ठा वेप to heat produced in the field winding by eddy currents
29. D.C. motor would be preferred for conveyors :
(A) Series motor (8) Shunt motor
(C) Differentially compound motor (D) Cumulative compound motor
30. What will happen if the back e.m.f, of a D.C. motor vanishes suddenly ?
(ಗಿ) The motor will stop (18) The motor will continue to run
(C) The armature may burn (0) The maotor will run noisy
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31. Ward - Leonard system of dc motor speed control is not recommended for :
(ക) Very low speed (8) Frequent motor reversals
(८) Constant speed operation (D) Wide speed change
32. Among the following generators which one has poorest regulation ?
(ಗಿ) ஊக (8) shunt (C) long shunt (D) shart shunt
33. For stable parallel operation shunt generators are most suitable because their voltage
characteristics is :
(A) drooping (B) லட (C) ಗ್ರ (1) identical
34. Which winding will provide the higher e.m.f. for a D.C. generator when the number of poles
and the number of armature conductors is fixed ?
(A) Wave winding
ए) Lap winding
(ल) Depends on other features of design
(11) Either of (A) and (B} abave
35. Asingle phase motor :
(A) Requires only one winding (ए) Can rotate in one direction only
(9) Is not self starting (12) Is self starting
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