Electrical Machines Which of the following represents the pitch factor? Cos α Cos (α/2) sin (α/2) Cos α² Cos α Cos (α/2) sin (α/2) Cos α² ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A belt-driven cumulatively-compound dc generator is delivering power to the dc mains. If the Belt snaps then the machine will run as a cumulative compounded motor in opposite direction cumulative compounded motor in the same direction differentially compounded motor in the opposite direction differentially compounded motor in the same direction cumulative compounded motor in opposite direction cumulative compounded motor in the same direction differentially compounded motor in the opposite direction differentially compounded motor in the same direction ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the load current and the flux of a DC motor are held constant and voltage applied across its armature is increased by 5%, the speed of the motor will reduce by 5 %. depend on other factors. remain unchanged. increase by 5 %. reduce by 5 %. depend on other factors. remain unchanged. increase by 5 %. 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, 3, 5 2, 3 , 5 2, 4 ,5 1, 4 1, 3, 5 2, 3 , 5 2, 4 ,5 1, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two 3-phase AC generators are such that one has twice the linear dimensions of the other. The field windings of each are excited to give identical sinusoidal air-gap flux density waveform. Both have the same number of stator slots and identical winding patterns. The conductor/slot in a big generator is K times that of the smaller one. The value of K to get equal no load voltage at same frequency is 1/2. 8. 4. 1/4. 1/2. 8. 4. 1/4. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC motors are stopped by opening line switches and not by forcing the handle of the motor starter back to OFF position. This is due to occurance of Heavy sparking at the first stud of starting resistance steps. Both of above. None of these. Heavy sparking at brushes. Heavy sparking at the first stud of starting resistance steps. Both of above. None of these. Heavy sparking at brushes. ANSWER DOWNLOAD EXAMIANS APP