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 0.5 p.u 0.125 p.u 0.25 p.u 0.75 p.u 0.5 p.u 0.125 p.u 0.25 p.u 0.75 p.u ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following voltage regulation method is accurate ? MMf method American standard association method ZPF method Synchronous impedance method MMf method American standard association method ZPF method Synchronous impedance method ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machines internal characteristics are plotted between Eg vs load current Eg vs Ia Vt vs load current Vt vs Ia Eg vs load current Eg vs Ia Vt vs load current Vt vs Ia ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer has resistance and reactance in per unit as 0.01 and 0.04 respectively. Its voltage regulation for 0.8 power factor lagging and leading will be 4.8% and -3.2% 6% and -4% 3.2% and -1.6% None of these 4.8% and -3.2% 6% and -4% 3.2% and -1.6% None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A smaller air gap in a polyphase induction motor helps to increase the starting torque. reduce the magnetizing current. reduce the chance of crawling. reduce the chance of cogging. increase the starting torque. reduce the magnetizing current. reduce the chance of crawling. reduce the chance of cogging. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If iron loss and full load copper loss of any transformer are denoted by Pi and Pc, then the load corresponding to maximum efficiency is given by (Pi / Pc)1.6 × full Load. (Pi / Pc) × full Load. (Pi / Pc)0.5 × Full Load. (Pi / Pc)2 × full Load. (Pi / Pc)1.6 × full Load. (Pi / Pc) × full Load. (Pi / Pc)0.5 × Full Load. (Pi / Pc)2 × full Load. ANSWER DOWNLOAD EXAMIANS APP
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