Electrical Machines If the full load speed of 3-phase, 50Hz induction motor is 950 rpm, what is its half load speed nearly equals to? 975 rpm 950 rpm 940 rpm 1000 rpm 975 rpm 950 rpm 940 rpm 1000 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be 57.1%. 88.8%. 59.2%. 48.0%. 57.1%. 88.8%. 59.2%. 48.0%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In which of the following DC Motor the ratio of starting torque to full load torque is minimum? Cumulative compound motor. Shunt motor. Series motor. Differential compound motor. Cumulative compound motor. Shunt motor. Series motor. Differential compound motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In dc machines, 1. reactance voltage is proportional to armature current 2.reactance voltage is proportional to core length 3.reactance voltage is due to self-flux of the coil undergoing commutation 4. armature-cross flux is neutralized by interpolar flux 5. interpolarmmf is more than armature mmf in the interpolar zone From these, the correct answer is 1, 3, 5 1, 2, 5 1, 2, 3, 4 2, 3, 4 1, 3, 5 1, 2, 5 1, 2, 3, 4 2, 3, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a three phase slip-ring induction motor, brushes are connected to external star-connected resistors. DC supply. equalizing coils. 3 - Φ AC supply. external star-connected resistors. DC supply. equalizing coils. 3 - Φ AC supply. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Rotor resistance speed control is used in squirrel cage induction motor. synchronous motor. slip ring induction motor. dc shunt motor. squirrel cage induction motor. synchronous motor. slip ring induction motor. dc shunt motor. ANSWER DOWNLOAD EXAMIANS APP
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