Electrical Machines Direction of rotation of DC motor is reversed by Reversing armature connection or field connection. Interchanging armature and field connection. Adding resistance to field circuit. Reversing supply connection. Reversing armature connection or field connection. Interchanging armature and field connection. Adding resistance to field circuit. Reversing supply connection. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the mechanical power developed by a DC series motor is maximum? Back emf is equal to applied voltage. Back emf is equal to zero. None of above. Back emf is equal to half the applied voltage. Back emf is equal to applied voltage. Back emf is equal to zero. None of above. Back emf is equal to half the applied voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The output voltage of a DC generator is E = V + Ra. E = V + IaRa. E = V + Ia. E = V – IaRa. E = V + Ra. E = V + IaRa. E = V + Ia. E = V – IaRa. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In synchronous motor the torque is proportional to P² 1/P 1/P² Power P P² 1/P 1/P² Power P ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The brushes of a DC machine should be placed on the armature midway between poles. commutator in the inter polar axis. armature in the polar axis. commutator in the polar axis. armature midway between poles. commutator in the inter polar axis. armature in the polar axis. commutator in the polar axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC motors are stopped by opening line switches and not by forcing the handle of the motor starter back to OFF position. This is due to occurance of Both of above. None of these. Heavy sparking at brushes. Heavy sparking at the first stud of starting resistance steps. Both of above. None of these. Heavy sparking at brushes. Heavy sparking at the first stud of starting resistance steps. ANSWER DOWNLOAD EXAMIANS APP