Electrical Machines To control the speed of an induction motor, the supply frequency is reduced by 10%. For the same magnetizing current to remain constant, the supply voltage must be reduced by 10% increased by 10% increased by 20% reduced by 20% reduced by 10% increased by 10% increased by 20% reduced by 20% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following statement is correct, if short circuit ratio is high? Low short circuit current None of these Good voltage regulation High voltage regulation Low short circuit current None of these Good voltage regulation High voltage regulation ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In double cage induction motor, the outer cage offers high resistance and high reactance. low resistance and high reactance. low resistance and low reactance. high resistance and low reactance. high resistance and high reactance. low resistance and high reactance. low resistance and low reactance. high resistance and low reactance. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The mmf produced by rotor currents of a 3 - Φ induction motor rotates at synchronous speed with respect to rotor. rotates at slip speed with respect to stator mmf. rotates at the speed of rotor in the air gap. is at standstill with respect to stator mmf. rotates at synchronous speed with respect to rotor. rotates at slip speed with respect to stator mmf. rotates at the speed of rotor in the air gap. is at standstill with respect to stator mmf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc series motor driving and electric train faces a constant power load. It is running at rated speed and rated voltage. If the speed has to be brought down to 0.25 p.u. the supply voltage has to be approximately brought down to 0.25 p.u 0.5 p.u 0.75 p.u 0.125 p.u 0.25 p.u 0.5 p.u 0.75 p.u 0.125 p.u ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator the emf generated by the armature is maximum when shaft rotation is high. induced voltage is high. rate of change of flux is maximum. rate of change of flux is minimum. shaft rotation is high. induced voltage is high. rate of change of flux is maximum. rate of change of flux is minimum. ANSWER DOWNLOAD EXAMIANS APP
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