Electrical Machines If the applied voltage of a certain transformer is increased by 50% and the frequency is reduced by 50%, the maximum flux density will (assuming that the magnetic circuit remains unsaturated) changes to 0.5 times the original value remain the same as the original changes to 1.5 times the original value changes to three times the original value changes to 0.5 times the original value remain the same as the original changes to 1.5 times the original value changes to three times the original value ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC motors are stopped by opening line switches and not by forcing the handle of the motor starter back to OFF position. This is due to occurance of Heavy sparking at the first stud of starting resistance steps. None of these. Both of above. Heavy sparking at brushes. Heavy sparking at the first stud of starting resistance steps. None of these. Both of above. Heavy sparking at brushes. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the applied voltage to a dc machine is 230 V, then the back emf, for maximum power developed, is 460 V 115 V 230 V 200 V 460 V 115 V 230 V 200 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC machine shape of main field flux distribution is? peaky in nature flat tapped or trapezoidal triangular saddle shape peaky in nature flat tapped or trapezoidal triangular saddle shape ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines which of the following losses are negligible in blocked rotor test? both A and B iron loss copper loss mechanical loss both A and B iron loss copper loss mechanical loss ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The principle of operation of a 3 - Φ induction motor is almost similar to that of capacitor start induction motor. synchronous motor. repulsion start induction motor. transformer with secondary short circuited. capacitor start induction motor. synchronous motor. repulsion start induction motor. transformer with secondary short circuited. ANSWER DOWNLOAD EXAMIANS APP