Electrical Machines The armature mmf of a DC machine has triangular space distribution and rotates at the speed of armature. trapezoidal space distribution and is stationary in space. stepped distribution and rotates at the speed of armature. triangular space distribution and is stationary in space. triangular space distribution and rotates at the speed of armature. trapezoidal space distribution and is stationary in space. stepped distribution and rotates at the speed of armature. triangular space distribution and is stationary in space. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a loaded DC generator, if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will improve with fall of terminal voltage. deteriorate with fall of terminal voltage. deteriorate with rise in terminal voltage. improve with rise in terminal voltage. improve with fall of terminal voltage. deteriorate with fall of terminal voltage. deteriorate with rise in terminal voltage. improve with rise in terminal voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 67.5% 82.5% 78.5% 72.5% 67.5% 82.5% 78.5% 72.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The 3 - Φ induction motor with rotor circuit open will run normally. not run. get over heated. make noise. run normally. not run. get over heated. make noise. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole DC generator runs at 750 rpm and generate an emf of 240 V. The armature is wave wound and has 792 conductors. If the total flux from each pole is 0.0145 Wb. What is the leakage co-efficient? 1.4. 1.8. 1.5. 1.2. 1.4. 1.8. 1.5. 1.2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A cumulatively compounded dc motor delivers rated load power at rated speed. If the series field is short-circuited, then both decrese both armature current Ia and speed ωm increase Ia increases and ωm decreses Ia remains constant but ωm increase both decrese both armature current Ia and speed ωm increase Ia increases and ωm decreses Ia remains constant but ωm increase ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS