Electrical Machines A 3 - Φ induction motor draws an current of 50 A from mains when starts by direct switching. If an auto transformer with 60 % tapping is used for starting the current drawn from the mains will be 18. 36. 50. 80. 18. 36. 50. 80. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A lap wound DC machine has 400 conductors and 8 poles. The voltage induced per conductor is 2 volts. The machine generates a voltage of 800 V. 200 V. 100 V. 400 V. 800 V. 200 V. 100 V. 400 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer has maximum efficiency at 3/4 load. The ratio of iron loss and full load copper loss is 3/4. 9/16. 4/3. 16/9. 3/4. 9/16. 4/3. 16/9. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a dc generator operating on load with its brushes on the geometrical neutral axis (GNA), the magnetic neutral axis (MNA) is shifted in the direction of rotation. Now, if the brushes are given a lead of 90° (electrical), then the MNA will shift forward by more than 90° shift forward by 90° coincide with the GNA shift forward by less than 90° shift forward by more than 90° shift forward by 90° coincide with the GNA shift forward by less than 90° ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a step down transformer which one of the following statements is true? Number of secondary turns is less than primary turns. Secondary current is less than primary current. Number of secondary turns is more than that of primary. Secondary power is less than primary power. Number of secondary turns is less than primary turns. Secondary current is less than primary current. Number of secondary turns is more than that of primary. Secondary power is less than primary power. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the full load speed of 3-phase, 50Hz induction motor is 950 rpm, what is its half load speed nearly equals to? 975 rpm 950 rpm 1000 rpm 940 rpm 975 rpm 950 rpm 1000 rpm 940 rpm ANSWER DOWNLOAD EXAMIANS APP