Electrical Machines In a synchronous motor, damper windings are provided on stator frame. rotor shaft. pole faces. None of these stator frame. rotor shaft. pole faces. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines How can the synchronous speed of a 3 - Φ IM be varied? By varying supply voltage. By varying number of poles. By varying the supply frequency. Both (A) and (B). By varying supply voltage. By varying number of poles. By varying the supply frequency. Both (A) and (B). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A commutator with a diameter of 50 cm rotating at 1000 rpm. For a brush width of 1.5 cm, find the time of commutation in ms. 0.649. 0.443. 0.573. 0.512. 0.649. 0.443. 0.573. 0.512. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to over commutation. any of the above. too rapid reversal of current. under commutation. over commutation. any of the above. too rapid reversal of current. under commutation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The function of field regulator in a DC compound motor is to vary the armature resistance. limit the armature current. none of above. control field current. vary the armature resistance. limit the armature current. none of above. control field current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When two DC series motors are connected in parallel, the resultant speed is more than normal speed. less than normal speed. normal speed. zero. more than normal speed. less than normal speed. normal speed. zero. ANSWER DOWNLOAD EXAMIANS APP