Electrical Machines For the speed control of polyphase squirrel cage induction motor, if frequency of operation is decreased with constant supply voltage V, starting torque Tst decreases constant V, Tst increases None of these either of these constant supply voltage V, starting torque Tst decreases constant V, Tst increases None of these either of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in dc motor results decrease in speed. short circuit. open circuit. increase in speed. decrease in speed. short circuit. open circuit. increase in speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two generators G1 and G2 are to be operated in parallel to deliver a total current of 60 A. Generator one has a terminal voltage of 280 V on no load and 240 V when supplying 40 A current. Similarly the second generator has a voltage of 300 V when on no load and 240 V when supplying of 50 A of current. The output voltage of each generator will be 271.7 V. 238.2 V. 240 V. 256.4 V. 271.7 V. 238.2 V. 240 V. 256.4 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A commutator with a diameter of 50 cm rotating at 1000 rpm. For a brush width of 1.5 cm, find the time of commutation in ms. 0.573. 0.649. 0.512. 0.443. 0.573. 0.649. 0.512. 0.443. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the mechanical power developed by a DC series motor is maximum? Back emf is equal to half the applied voltage. None of above. Back emf is equal to applied voltage. Back emf is equal to zero. Back emf is equal to half the applied voltage. None of above. Back emf is equal to applied voltage. Back emf is equal to zero. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If dimension of all the parts of a synchorous generator and the number of field and armature turns are double, then generated voltage will change by a factor of 1. 4. 2. 8. 1. 4. 2. 8. ANSWER DOWNLOAD EXAMIANS APP
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