Electrical Machines A DC generator without commutator is a AC generator induction motor DC generator DC motor AC generator induction motor DC generator DC motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3 - Φ wound rotor induction motor the short circuit gear is used to short circuit the starting resistance in the starter. None of these stator phases of the motor. rotor at slip rings. starting resistance in the starter. None of these stator phases of the motor. rotor at slip rings. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What will be the e.m.f. generated by a 4 pole lap connected DC Generator rotating at 1500 r.p.m.? Its flux per pole is 0.4 mWb and total no of armature conductors is 1000. 10 volts. 20 volts. 30 volts. 40 volts. 10 volts. 20 volts. 30 volts. 40 volts. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If we increase the rotor reactance value, the maximum torque will increase decrease not changed None of these increase decrease not changed None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If Pi and Pc represent core and full load copper loss respectively, the maximum KVA delivered to load corresponding to maximum efficiency is equal to rated KVA is (Pi/Pc)2 √(Pi/Pc) Pi/Pc Pc/Pi (Pi/Pc)2 √(Pi/Pc) Pi/Pc Pc/Pi ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes : 1 and 3 1, 2, and 3 2, 3 and 4 1, 2 and 4 1 and 3 1, 2, and 3 2, 3 and 4 1, 2 and 4 ANSWER DOWNLOAD EXAMIANS APP