Electrical Machines If the number of rotor slots is equal to number of stator slots, then motor refuses to start. Hence it is known as air gap. crawling. relative speed. cogging. air gap. crawling. relative speed. cogging. 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, 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 2, 3 and 4 are correct 1, 2 and 4 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole 50 Hz 1-phase induction motor is running at 1470 rpm. Find the forward and backward slips? 0.02, 0.98 0.04, 1.96 0.04, 0.96 0.02, 1.98 0.02, 0.98 0.04, 1.96 0.04, 0.96 0.02, 1.98 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to under commutation. too rapid reversal of current. any of the above. over commutation. under commutation. too rapid reversal of current. any of the above. over commutation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When flux density is constant in a transformer, hysteresis loss varies as V² V f f² V² V f f² ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation is reduced, the power factor is lagging power factor unity power factor leading power factor None of these lagging power factor unity power factor leading power factor None of these ANSWER DOWNLOAD EXAMIANS APP
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