Electrical Machines When excitation is increased (over excitation), the synchronous generator operates at any of the above. lagging power factor. leading power factor. unity power factor. any of the above. lagging power factor. leading power factor. unity power factor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The magnetic circuit of a dc shunt generator with negligible armature resistance and brush contact voltage drop remains unsaturated when it delivers full-load current at rated terminal voltage. The brushes are kept in the interpolar axis and speed is maintained constant. When the load is switched off, the terminal voltage would decrease become zero increase remain the same decrease become zero increase remain the same 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 Ia increases and ωm decreses both decrese both armature current Ia and speed ωm increase Ia remains constant but ωm increase Ia increases and ωm decreses both decrese both armature current Ia and speed ωm increase Ia remains constant but ωm increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For higher values of armature, the speed of a DC series motor is Proportional to armature current. Proportional to the square of armature current. Inversely proportional to armature current. Constant. Proportional to armature current. Proportional to the square of armature current. Inversely proportional to armature current. Constant. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-phase, 50 Hz, 4 pole induction motor is running at 1440 rpm. Find the rotor efficiency? 96% 92% 94% 95% 96% 92% 94% 95% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Cogging of induction motor occurs at high voltage and when stator and rotor poles are equal. high voltage and when stator and rotor poles are not equal. low voltage and when stator and rotor poles are not equal. low voltage and when stator and rotor poles are equal. high voltage and when stator and rotor poles are equal. high voltage and when stator and rotor poles are not equal. low voltage and when stator and rotor poles are not equal. low voltage and when stator and rotor poles are equal. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS