Electrical Machines A 3-phase, 50 Hz, 4 pole induction motor is running at 1440 rpm and rotor input power is 2KW. Find the rotor copper loss? 80W 100W 60W 40W 80W 100W 60W 40W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To control the speed of an induction motor, the supply frequency is reduced by 10%. For the same magnetizing current to remain constant, the supply voltage must be reduced by 20% reduced by 10% increased by 10% increased by 20% reduced by 20% reduced by 10% increased by 10% increased by 20% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The residual magnetism of a self-excited dc generator is lost. To build up its emf again 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 the field winding connection must be reversed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If in a sub – station there is one 132 / 33 kV transformer whose secondary is connected with primary of one 33 / 11 kV transformer, the total transformation ratio of the sub – station will be, 4. 12. 3. 7. 4. 12. 3. 7. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following induction motor has the highest starting torque? None of these Same in both induction motors. Slip ring induction motor. Squirrel cage induction motor. None of these Same in both induction motors. Slip ring induction motor. Squirrel cage induction motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Find the developed torque DC Series Motor having armature resistance of 0.2 Ω and taking armature current of 60 A is connected to 250 V supply. Considered brush drop of 1 V each. 266.20 N-m. cant be determined. 234.76 N-m. 133.22 N-m 266.20 N-m. cant be determined. 234.76 N-m. 133.22 N-m ANSWER DOWNLOAD EXAMIANS APP