Electrical Machines In case of induction motors the ratio of length to pole pitch for minimum cost, is taken as 1.5 to 2. 3 to 5. 1.0. 2 to 3. 1.5 to 2. 3 to 5. 1.0. 2 to 3. 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 2, 3 and 4 1, 2 and 4 1, 2, and 3 1 and 3 2, 3 and 4 1, 2 and 4 1, 2, and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An induction motor having 8 poles runs at 727.5 rpm. If the supply frequency is 50Hz, the emf in the rotor will have a frequency of 51.5Hz 1.5Hz 48.5Hz 2.5Hz 51.5Hz 1.5Hz 48.5Hz 2.5Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the frequency of input voltage of a transformer is increased keeping the magnitude of voltage unchanged, then both hysteresis loss(Ph) and eddy current loss(Pe) will increase Pe will increase but Ph will decrease Ph will increase but Pe will decrease Ph will decrease but Pe will remain same both hysteresis loss(Ph) and eddy current loss(Pe) will increase Pe will increase but Ph will decrease Ph will increase but Pe will decrease Ph will decrease but Pe will remain same ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Generators work on the principle of production of dynamically and statically induced emf. statically induced emf. dynamically induced emf. None of these dynamically and statically induced emf. statically induced emf. dynamically induced emf. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A short circuit test on a transformer gives copper loss at any load. copper loss at half load. copper loss at over load. copper loss at full load. copper loss at any load. copper loss at half load. copper loss at over load. copper loss at full load. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS