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? 100W 80W 60W 40W 100W 80W 60W 40W ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In which of the following motors DC excitation is not required? hysteresis motor 3-phase synchronous generator reluctance motor 3-phase synchronous motor hysteresis motor 3-phase synchronous generator reluctance motor 3-phase synchronous motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two mechanically coupled alternators deliver power at 50 Hz and 60 Hz respectively. The highest speed of the alternators is 3000 rpm. 600 rpm. 3600 rpm. 500 rpm. 3000 rpm. 600 rpm. 3600 rpm. 500 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The mechanical power is developed by a DC motor is maximum when back emf is equal to applied voltage. back emf is equal to half of applied voltage. back emf is equal to twice of applied voltage. none of above. back emf is equal to applied voltage. back emf is equal to half of applied voltage. back emf is equal to twice of applied voltage. none of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the armature electric current is increased to double its previous value, and the time of commutation is halved, how will the reactance voltage vary? It will be halved. It will becomes four times. It will be doubled. It will remain the same. It will be halved. It will becomes four times. It will be doubled. It will remain the same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A smaller air gap in a polyphase induction motor helps to reduce the magnetizing current. reduce the chance of crawling. reduce the chance of cogging. increase the starting torque. reduce the magnetizing current. reduce the chance of crawling. reduce the chance of cogging. increase the starting torque. ANSWER DOWNLOAD EXAMIANS APP
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