Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 1, 3 1, 4 2, 4 2, 3 1, 3 1, 4 2, 4 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In an alternator the voltage generated per phase is proportional to frequency of waveform. All of these number of turns in coil. flux per pole. frequency of waveform. All of these number of turns in coil. flux per pole. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a three phase star - delta transformer, what is the angle difference between primary and secondary phase voltages? Delta side leads by 30°. Delta side lags by -30°. Star side leads by 30°. Star side lags by -30°. Delta side leads by 30°. Delta side lags by -30°. Star side leads by 30°. Star side lags by -30°. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The shaft torque of a dc motor is less than the electromagnetic torque because of mechanical losses. ohmic losses. hysteresis losses. eddy current losses. mechanical losses. ohmic losses. hysteresis losses. eddy current losses. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Ward Leonard control is provides speed control Above rated speed. In one direction only. Below rated speed. In both direction. Above rated speed. In one direction only. Below rated speed. In both direction. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The power factor of an induction motor operating at no load will have a value around 0.9 lag 0.2 lag 0.2 lead unity 0.9 lag 0.2 lag 0.2 lead unity ANSWER DOWNLOAD EXAMIANS APP