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. increased. remains unchanged. decreased. kept constant to certain value. increased. remains unchanged. decreased. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If s is the slip and f is the supply frequency of an induction motor, the frequency of rotor current is given by sf / 2. sf. s2. f / s. sf / 2. sf. s2. f / s. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to under commutation. any of the above. too rapid reversal of current. over commutation. under commutation. any of the above. too rapid reversal of current. over commutation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of rotation of conductor of a DC motor can be determined by Fleming's left hand rule. Ampere law. Fleming's right hand rule. Lenz's law. Fleming's left hand rule. Ampere law. Fleming's right hand rule. Lenz's law. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In induction motor the 7th harmonic torque may make the motor rotate at (1 / 7)th synchronous speed. This is called crawling. resonance. cogging. harmonics. crawling. resonance. cogging. harmonics. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a loaded DC generator, if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will deteriorate with fall of terminal voltage. improve with fall of terminal voltage. deteriorate with rise in terminal voltage. improve with rise in terminal voltage. deteriorate with fall of terminal voltage. improve with fall of terminal voltage. deteriorate with rise in terminal voltage. improve with rise in terminal voltage. ANSWER DOWNLOAD EXAMIANS APP
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