Electrical Machines If direct axis reactance Xd and quadrature axis reactance Xq are equal, then reluctance power is All of these zero minimum maximum All of these zero minimum maximum 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 Two identical loss less series motors connected in series across a dc supply voltage, runs at speed of N1 and N2, then ratio of their output power is N12 : N22. 1 : 1. none. N1 : N2. N12 : N22. 1 : 1. none. N1 : N2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum efficiency will occur, when copper loss is_______to iron loss? less than equal to any of the above greater than less than equal to any of the above greater than ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous motor torque or load angle δ ------------- with increase in load decreases increases remains unaffected None of these decreases increases remains unaffected None of these 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 : 2, 3 and 4 1, 2 and 4 1 and 3 1, 2, and 3 2, 3 and 4 1, 2 and 4 1 and 3 1, 2, and 3 ANSWER DOWNLOAD EXAMIANS APP