Electrical Machines A dc shunt motor has external resistance Ra and Rf in the armature and field circuits respectively. Armature current at starting can be reduced by keeping Ra minimum and Rf minimum Ra maximum and Rf minimum Rf maximum and Ra minimum Ra maximum and Rf maximum Ra minimum and Rf minimum Ra maximum and Rf minimum Rf maximum and Ra minimum Ra maximum and Rf maximum ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of DC Shunt Motor, the speed will____ if the voltage increases, neglecting armature saturation. increase decrease. be unpredictable. remain the same. increase decrease. be unpredictable. remain the same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC machine, the angle between the stator and rotor fields is dependent upon the load. 0o. 90o. 180o. dependent upon the load. 0o. 90o. 180o. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A simple method of increasing the voltage of a DC generator is to increase the number of turns in field coil. increase the speed of shaft rotation. increase the source frequency. increase the number of turns in armature coil. increase the number of turns in field coil. increase the speed of shaft rotation. increase the source frequency. increase the number of turns in armature coil. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a transformer which of the following losses are zero? Rotational loss All of these Iron loss Copper loss Rotational loss All of these Iron loss Copper loss ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-φ alternator has negligible stator resistance. A short circuit test is conducted on this alternator. At a particular speed, a field current of If1 is required to drive the rated armature current. If the speed of the alternator is reduced to half, the field current required to maintain rated armature current Would be equal to If1. Cannot be predicted due to insufficient data. Would be equal to If1/2. Woud be equal to 2If1. Would be equal to If1. Cannot be predicted due to insufficient data. Would be equal to If1/2. Woud be equal to 2If1. ANSWER DOWNLOAD EXAMIANS APP
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