Electrical Machines In an induction motor, what is the ratio of rotor input to rotor copper loss? S 1-S 1/(1-S) 1/S S 1-S 1/(1-S) 1/S ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The main disadvantage(s) of the ward-Leonard system is/are high maintenance cost. poor overall efficiency. high initial cost. all of above. high maintenance cost. poor overall efficiency. high initial cost. all of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The condition for maximum running torque is 0.707 lagging zero 0.5 lagging R = S.X unity 0.707 lagging zero 0.5 lagging R = S.X unity ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc series motor driving and electric train faces a constant power load. It is running at rated speed and rated voltage. If the speed has to be brought down to 0.25 p.u. the supply voltage has to be approximately brought down to 0.75 p.u 0.25 p.u 0.125 p.u 0.5 p.u 0.75 p.u 0.25 p.u 0.125 p.u 0.5 p.u 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 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° shift forward by more than 90° ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The field divertor resistance for a DC series motor is of order of 100 Ω 0.1 Ω 50 Ω 10 Ω 100 Ω 0.1 Ω 50 Ω 10 Ω ANSWER DOWNLOAD EXAMIANS APP