Electrical Machines A 3-phase, 50Hz, 4 pole induction motor is running at 1440 rpm and rotor input power is 2KW. Find the rotor output power? 2000W 1450W 1820W 1920W 2000W 1450W 1820W 1920W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The supply voltage to an induction motor is reduced by 10%. By what percentage, approximately, will the maximum torque decrease? 40% 19% 5% 10% 40% 19% 5% 10% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The residual magnetism of a self-excited dc generator is lost. To build up its emf again the field winding connection must be reversed field winding must be excited by low voltage dc supply the field winding must be replaced the armature connection must be reversed the field winding connection must be reversed field winding must be excited by low voltage dc supply the field winding must be replaced the armature connection must be reversed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The compensating winding in a DC machine is located in armature slots for compensation of the armature reaction. is located on pole shoes for avoiding the flashover at the commutator. is located on commutating poles for improving commutation. is located on pole shoes to avoid the sparking at the brushes. is located in armature slots for compensation of the armature reaction. is located on pole shoes for avoiding the flashover at the commutator. is located on commutating poles for improving commutation. is located on pole shoes to avoid the sparking at the brushes. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the number of rotor slots is equal to number of stator slots, then motor refuses to start. Hence it is known as air gap. cogging. crawling. relative speed. air gap. cogging. crawling. relative speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a step down transformer which one of the following statements is true? Number of secondary turns is more than that of primary. Number of secondary turns is less than primary turns. Secondary power is less than primary power. Secondary current is less than primary current. Number of secondary turns is more than that of primary. Number of secondary turns is less than primary turns. Secondary power is less than primary power. Secondary current is less than primary current. ANSWER DOWNLOAD EXAMIANS APP