Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? All of these They are self lubricating in nature They are not hard as copper brush In case of any sparking they will be less damaged than copper brushes All of these They are self lubricating in nature They are not hard as copper brush In case of any sparking they will be less damaged than copper brushes ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : 1. interpole windings are connected in series with armature windings 2. polarity of interpoles must be the same as that of the main poles in advance 3. distortion of the main field under the pole shoes is not affected by the use of interpoles From above, the correct answer is 1 and 3 1 and 2 2 and 3 1 alone 1 and 3 1 and 2 2 and 3 1 alone ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The flux involved in the emf equation of a transformer has rms value. average value. maximum value. total value. rms value. average value. maximum value. total value. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Hunting phenomenon is observed in which motor? Induction motor. DC motor. Synchronous motor. Both A and C. Induction motor. DC motor. Synchronous motor. Both A and C. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Counter emf of a DC motor regulates its armature voltage. helps in energy conversion. aids applied voltage. exceeds supply voltage regulates its armature voltage. helps in energy conversion. aids applied voltage. exceeds supply voltage ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The results of a slip test for determining direct axis (Xd) and quadrature axis (Xq) reactances of a star connected salient pole alternator are given below Phase values: Vmax = 108 V ; Vmin = 96 V Imax = 12 A ; Imin = 10 A Hence the two reactances will be Xd = 10.8Ω and Xq = 8Ω Xd = 9.6Ω and Xq = 9Ω Xd = 8Ω and Xq = 10.8Ω Xd = 9Ω and Xq = 9.6Ω Xd = 10.8Ω and Xq = 8Ω Xd = 9.6Ω and Xq = 9Ω Xd = 8Ω and Xq = 10.8Ω Xd = 9Ω and Xq = 9.6Ω ANSWER DOWNLOAD EXAMIANS APP
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