Electrical Machines In an alternator, voltage drops occurs in armature resistance and leakage reactance. armature resistance, leakage reactance and armature reaction. armature resistance, leakage reactance, armature reaction and earth connection. armature resistance only. armature resistance and leakage reactance. armature resistance, leakage reactance and armature reaction. armature resistance, leakage reactance, armature reaction and earth connection. armature resistance only. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A three phase induction motor has a synchronous speed of 1500 rpm the machine runs at 1460 rpm at a particular load. The slip at this load is ___________. 1.5 %. 2.67 %. 5 %. 30 %. 1.5 %. 2.67 %. 5 %. 30 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor must started on no load because it would Run at dangerously high speed. Fail to start without load. Not develop starting torque. Draw more current without producing sufficient torque. Run at dangerously high speed. Fail to start without load. Not develop starting torque. Draw more current without producing sufficient torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the mechanical power developed by a DC series motor is maximum? Back emf is equal to zero. Back emf is equal to half the applied voltage. Back emf is equal to applied voltage. None of above. Back emf is equal to zero. Back emf is equal to half the applied voltage. Back emf is equal to applied voltage. None of above. 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 1 and 3 1, 2 and 4 2, 3 and 4 1, 2, and 3 1 and 3 1, 2 and 4 2, 3 and 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The DC generator runs at a speed of 1000 rpm and flux per pole is 0.2 Wb, number of poles are 2 the winding is wave wound and having 480 conductors. The critical speed is 1200 rpm. Then the generated emf ( Eg ) 1500 Volt. 2000 Volt. 0 Volt. 1600 Volt. 1500 Volt. 2000 Volt. 0 Volt. 1600 Volt. ANSWER DOWNLOAD EXAMIANS APP