Electrical Machines A DC series motor is running at rated speed without any additional resistance in series. If an additional resistance is placedin series, the speed of motor Remains unchanged. Increases. Decreases. Oscillates around the rated speed. Remains unchanged. Increases. Decreases. Oscillates around the rated speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately-excited DC generator, running at rated speed, has 6 volts across its armature terminals with no field current. When field winding is excited with one ampere, the voltage builds up to 250 V at no load. In case field current is reduced to zero, with the speed remaining unaltered, the armature terminal voltage would be less than 6 V more than 6 V 6 V zero less than 6 V more than 6 V 6 V zero ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The short circuit test on a transformer is conducted to obtain hysteresis loss. copper losses. core loses only. eddy current loss. hysteresis loss. copper losses. core loses only. eddy current loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the frequency of a alternator, if P = number of poles and N = revolution made per second? 120P / N Hz. 120 / PN Hz. 120N / P Hz. PN / 2 Hz. 120P / N Hz. 120 / PN Hz. 120N / P Hz. PN / 2 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator if field winding attains the critical resistance machine will generate maximum power. the voltage generated will be zero. field winding will burn. machine will generate maximum voltage. machine will generate maximum power. the voltage generated will be zero. field winding will burn. machine will generate maximum voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For the above problem, find the induced voltage of an alternator of it is to deliver a load of 100 A at power factor of 0.8 lagging with terminal voltage of 200 V. 230 V. 222 V. 220 V. 225 V. 230 V. 222 V. 220 V. 225 V. ANSWER DOWNLOAD EXAMIANS APP