Electrical Machines For 250 volt DC Shunt Motor the armature and field resistance are 0.5 ohm and 250 ohm respectively. What will be the back e.m.f. produced when it takes a load current of 21A. 150 V. 240 V. 280 V. 220 V. 150 V. 240 V. 280 V. 220 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Thin laminations are used in a machine in order to reduce Eddy current losses Both 1 and 2 Hysteresis losses Copper losses Eddy current losses Both 1 and 2 Hysteresis losses Copper losses ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In induction motor when the length of the air gap is increased, the magnetizing current of the motor increases while the short circuit current __________________. kept constant to certain value. decreased. increased. remains unchanged. kept constant to certain value. decreased. increased. remains unchanged. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous motor when the rotor speed exceeds the synchronous speed during hunting the damper bars develop induction generator torque. negative sequence currents are generated. the damper bars develop synchronous motor torque. the damper bars develop induction motor torque. the damper bars develop induction generator torque. negative sequence currents are generated. the damper bars develop synchronous motor torque. the damper bars develop induction motor torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer core is made up of a silicon steel laminations which has maximum flux density 1 Tesla. If it was cold rolled grain oriented its flux density increases to 1.6 Tesla. What is the saving in core size or area due to cold rolled grain oriented process? 60% 38% 68% 40% 60% 38% 68% 40% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines With the increases in field excitation of a DC generator, its generated emf increases. remains constant. increases upto a limit and then remains almost constant. decreases. increases. remains constant. increases upto a limit and then remains almost constant. decreases. ANSWER DOWNLOAD EXAMIANS APP
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