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 60W 100W 40W 80W 60W 100W 40W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machine torque is proportional to which of the following? armature current(Ia) flux(φ) both A and B None of these armature current(Ia) flux(φ) both A and B None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of generated emf in the armature coil of a DC machine is 1. the same as that of the current in a generator 2. the same as that of the current in a motor 3. opposite to that of the current in a generator 4. opposite to that of the current in a motor From these, the correct answer is 2, 3 1, 4 1, 3 2, 4 2, 3 1, 4 1, 3 2, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Flux density under trailing pole tips in case of generator will None of these either increase or decrease decrease increase None of these either increase or decrease decrease increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC shunt generator working on load, the brushes are moved forward in the direction of rotation, as a result of this, commutation will improve but terminal voltage will fall. improve and terminal voltage will rise . worsen and terminal voltage will rise. worsen and terminal voltage will fall improve but terminal voltage will fall. improve and terminal voltage will rise . worsen and terminal voltage will rise. worsen and terminal voltage will fall ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt generator builds up to a voltage of 220 V at no load while running at its rated speed. If the speed of the generator is raised by 25% kepping the circuit conditions unaltered, then the Voltage to which the machine would build up will not change and remain at 220 V increase to a value greater than 1.25 times 220 V increase to 1.25 times 220 V increase to value lying between 220 V and 1.25 times 220 V not change and remain at 220 V increase to a value greater than 1.25 times 220 V increase to 1.25 times 220 V increase to value lying between 220 V and 1.25 times 220 V ANSWER DOWNLOAD EXAMIANS APP