Electrical Machines In which of the following speed control of DC motor the speed obtained is below than the rated speed? Any of above. Field resistance control. Armature voltage control. Armature circuit resistance control. Any of above. Field resistance control. Armature voltage control. Armature circuit resistance control. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machine yoke offers produce working flux both A and B flux path completion mechanical protection to the machine produce working flux both A and B flux path completion mechanical protection to the machine 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, 2, and 3 1 and 3 2, 3 and 4 1, 2 and 4 1, 2, and 3 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When R2 is rotor resistance, X2 the rotor reactance at supply frequency and s the slip, then the condition for maximum torque under running condition will be R2 = sX2. R2 = s2X2. sR2 = X2. R2 = s2X2. R2 = sX2. R2 = s2X2. sR2 = X2. R2 = s2X2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following DC Motor uses 4-point starter? DC shunt motor with armature resistance. DC series motor. DC shunt motor with field weaking control. DC compound motor. DC shunt motor with armature resistance. DC series motor. DC shunt motor with field weaking control. DC compound motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The condition for maximum running torque is 0.707 lagging 0.5 lagging zero R = S.X unity 0.707 lagging 0.5 lagging zero R = S.X unity ANSWER DOWNLOAD EXAMIANS APP