Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to under commutation. over commutation. any of the above. too rapid reversal of current. under commutation. over commutation. any of the above. too rapid reversal of current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature flux is.............with respect to main field flux or main field poles? None of these rotates opposite direction rotates same direction stationary None of these rotates opposite direction rotates same direction stationary 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 = 8Ω and Xq = 10.8Ω Xd = 10.8Ω and Xq = 8Ω Xd = 9.6Ω and Xq = 9Ω Xd = 9Ω and Xq = 9.6Ω Xd = 8Ω and Xq = 10.8Ω Xd = 10.8Ω and Xq = 8Ω Xd = 9.6Ω and Xq = 9Ω Xd = 9Ω and Xq = 9.6Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ, 6 pole, 50 Hz IM is running at a full load speed of 980 rpm. If it delivers an air gap power of 98000 Watt, calculate the rotor ohmic loss? 1960 Watt. 1800 Watt. 980 Watt. 1920 Watt. 1960 Watt. 1800 Watt. 980 Watt. 1920 Watt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the increase in the torque expressed as percentage of initial torque, if current drawn by the dc series motor is increased from 10A to 11A? 21% 11% 41% 10% 21% 11% 41% 10% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor power output of 3-phase induction motor is 15 KW. The rotor copper losses at a slip of 4% will be 625 W 650 W 700 W 600 W 625 W 650 W 700 W 600 W ANSWER DOWNLOAD EXAMIANS APP
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