Electrical Machines If an additional resistance is connected in series with a DC series motor operating at rated speed, the speed of the motor will Reduce. Remain unaltered. Increase. Oscillate around the normal speed. Reduce. Remain unaltered. Increase. Oscillate around the normal speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In an alternator the voltage generated per phase is proportional to number of turns in coil. All of these flux per pole. frequency of waveform. number of turns in coil. All of these flux per pole. frequency of waveform. 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? 15.6 Nm Zero 16.55 Nm 15.28 Nm 15.6 Nm Zero 16.55 Nm 15.28 Nm 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 2, 3, 4 1, 2, 3, 4 1, 3, 5 1, 2, 5 2, 3, 4 1, 2, 3, 4 1, 3, 5 1, 2, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What will be the e.m.f. generated by a 4 pole lap connected DC Generator rotating at 1500 r.p.m.? Its flux per pole is 0.4 mWb and total no of armature conductors is 1000. 10 volts. 40 volts. 30 volts. 20 volts. 10 volts. 40 volts. 30 volts. 20 volts. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following represents the operating region of slip in a 1-phase induction motor? 0 < S < 2 -2 < S < 2 -1 < S < 1 0 < S < 1 0 < S < 2 -2 < S < 2 -1 < S < 1 0 < S < 1 ANSWER DOWNLOAD EXAMIANS APP