Electrical Machines A 4 pole 50 Hz induction motor is running at 1470 rpm. Find the speed of stator magnetic field with respect to rotor? 1470 rpm 30 rpm zero 1500 rpm 1470 rpm 30 rpm zero 1500 rpm 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 and 4 are correct 1, 2 and 4 are correct 1, 2 and 3 are correct 2, 3 and 4 are correct 1 and 4 are correct 1, 2 and 4 are correct 1, 2 and 3 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A transformer has resistance and reactance in per unit as 0.01 and 0.04 respectively. Its voltage regulation for 0.8 power factor lagging and leading will be None of these 4.8% and -3.2% 6% and -4% 3.2% and -1.6% None of these 4.8% and -3.2% 6% and -4% 3.2% and -1.6% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What are slot wedges in a DC machine made of? Silicon steel. Fibre. Cast iron. Mild steel. Silicon steel. Fibre. Cast iron. Mild steel. 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? 15.28 Nm Zero 16.55 Nm 15.6 Nm 15.28 Nm Zero 16.55 Nm 15.6 Nm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If starter is not used with large DC motor for starting, it will draw a starting current many times its rated full load current. all of above. provide execessive voltage drop in line. damage the armature and commutator. draw a starting current many times its rated full load current. all of above. provide execessive voltage drop in line. damage the armature and commutator. ANSWER DOWNLOAD EXAMIANS APP
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