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
Electrical Machines Demagnetization effects which of the following? both B and C commutation reduces the terminal voltage reduction in main field flux both B and C commutation reduces the terminal voltage reduction in main field flux ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 3 only 1, 2 and 3 1, 3 1, 2, 3 and 4 3 only 1, 2 and 3 1, 3 1, 2, 3 and 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net voltage across the armature resistance at the time of plugging will be 6 V 240 V 474 V 234 V 6 V 240 V 474 V 234 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a loaded DC motor, if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will improve and the speed rises. deteriorate and the speed falls. deteriorate and the speed rises. improve and the speed falls. improve and the speed rises. deteriorate and the speed falls. deteriorate and the speed rises. improve and the speed falls. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the rotor of a 3 phase induction motor is blocked then the slip is 0.54. 0.7. 1. 0.3. 0.54. 0.7. 1. 0.3. ANSWER DOWNLOAD EXAMIANS APP
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