Electrical Machines A shunt generator has a critical field resistance of 300 Ω at a speed of 800 rpm if the speed is raised to 1000 rpm the critical field resistance is 375 Ω. 145 Ω. 150 Ω. 225 Ω. 375 Ω. 145 Ω. 150 Ω. 225 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The basic function of a transformer is to change the power factor the level of the voltage the power level the frequency the power factor the level of the voltage the power level the frequency ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding dc machines : 1. possible resistance of shunt-field winding is 1 Ω 2. possible resistance of series-field winding is 1 Ω 3. electrographite brushes are used for 230 V, 10 A machines 4. Copper-graphite brushes are used for 230 V, 10 A machines 5. Possible armature-circuit resistance is 1 Ω From these, the correct statements are 1, 4 2, 4 ,5 1, 3, 5 2, 3 , 5 1, 4 2, 4 ,5 1, 3, 5 2, 3 , 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in a DC machine is in the same direction as the main poles. is in direct opposition to the main poles. makes an angle of 90° with the main pole axis. makes an angle with the main pole axis which is load dependent. is in the same direction as the main poles. is in direct opposition to the main poles. makes an angle of 90° with the main pole axis. makes an angle with the main pole axis which is load dependent. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is/are the necessary conditions for parallel operation of alternators? Terminal voltage is same Speed of alternators should be same Frequency should be same Both 1and 2 Terminal voltage is same Speed of alternators should be same Frequency should be same Both 1and 2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4-pole generator with 16 coil has a two layer lap winding. The pole pitch is 16. 4. 32. 8. 16. 4. 32. 8. ANSWER DOWNLOAD EXAMIANS APP
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