Electrical Machines A 3- phase synchronous motor can operate over a wide range of power factors i.e. from lagging to leading power factor. This is achieved by varying the speed. varying the applied voltage. changing the field excitation. changing the load. varying the speed. varying the applied voltage. changing the field excitation. changing the load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To have sparkless commutation, the armature reaction effect in a DC machine is neutralized by increasing field excitation. fixing the brush axis inline with the pole axis. compensating winding and commutating poles. shifting the brush axis from GNA to MNA. increasing field excitation. fixing the brush axis inline with the pole axis. compensating winding and commutating poles. shifting the brush axis from GNA to MNA. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the increase in the torque expressed as percentage of initial torque, if current drawn by the dc series motor is increased from 10A to 11A? 41% 11% 21% 10% 41% 11% 21% 10% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motor is suitable for frequent starting and stoppings? Capacitor start motor All of these Resistance split phase motor Capacitor start capacitor run motor Capacitor start motor All of these Resistance split phase motor Capacitor start capacitor run motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Pole changing methods are suitable only for ___________ type induction motor. wound. linear. none of these. cage. wound. linear. none of these. cage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately excited DC motor has an armature resistance of 0.5 Ohm. The supply voltage is 250V. Armature current is 20A and the speed of rotation is 1500 rpm. Find the torque developed? 16.55 Nm 15.6 Nm Zero 15.28 Nm 16.55 Nm 15.6 Nm Zero 15.28 Nm ANSWER DOWNLOAD EXAMIANS APP
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