Electrical Machines The armature mmf of a DC machine has trapezoidal space distribution and is stationary in space. triangular space distribution and is stationary in space. stepped distribution and rotates at the speed of armature. triangular space distribution and rotates at the speed of armature. trapezoidal space distribution and is stationary in space. triangular space distribution and is stationary in space. stepped distribution and rotates at the speed of armature. triangular space distribution and rotates at the speed of armature. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider a separately excited DC motor. If the field current is increased while the armature terminal voltage is held constant, then speed of the motor will increase. remains same. Decrease.d none of these. increase. remains same. Decrease.d none of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When maximum starting torque is obtained, rotor power is 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 : 1, 2, and 3 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 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor winding for a 3-phase slip-ring induction motor having delta-connected stator must be connected in delta. None of these delta or star according to need. star. delta. None of these delta or star according to need. star. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of rotation of a DC motor can be determent by Amperes law. Flemings left hand rule. Flemings right hand rule. Lenzs law. Amperes law. Flemings left hand rule. Flemings right hand rule. Lenzs law. ANSWER DOWNLOAD EXAMIANS APP