Electrical Machines When flux density is constant in a transformer, hysteresis loss varies as f² f V V² f² f V V² ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements about commutating poles which are fitted on most large dc Shunt motors: 1. The commutating poles are placed in the geometric neutral plane and their number is usually Equal to the number of main poles 2. The winding on the commutating poles is connected in series with the shunt-field winding on the main poles 3. The polarity of the commutating pole must be that of the next pole further ahead 4. The commutating poles neutralize the reactance voltage produced in the coil undergoing Commutation. Of these statements, 2, 3 and 4 are correct 1, 2 and 4 are correct 1, 2 and 3 are correct 1 and 4 are correct 2, 3 and 4 are correct 1, 2 and 4 are correct 1, 2 and 3 are correct 1 and 4 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature resistance control method is also called as-----------? constant torque control constant voltage control constant current control constant power control constant torque control constant voltage control constant current control constant power control ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which method is less recommendable for induction motor starting in the industries? Stator resistance starting. Direct online starting. Rotor resistance starting. Auto transformer starting. Stator resistance starting. Direct online starting. Rotor resistance starting. Auto transformer starting. 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 15.28 Nm Zero 16.55 Nm 15.6 Nm 15.28 Nm Zero ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-φ alternator has negligible stator resistance. A short circuit test is conducted on this alternator. At a particular speed, a field current of If1 is required to drive the rated armature current. If the speed of the alternator is reduced to half, the field current required to maintain rated armature current Would be equal to If1. Would be equal to If1/2. Woud be equal to 2If1. Cannot be predicted due to insufficient data. Would be equal to If1. Would be equal to If1/2. Woud be equal to 2If1. Cannot be predicted due to insufficient data. ANSWER DOWNLOAD EXAMIANS APP
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