Electrical Machines In a transformer zero voltage regulation is achieved at a load power factor which is lagging unity zero leading lagging unity zero leading ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the phase difference between two windings of A.C servomotor ? 90°. 60°. 120°. 30°. 90°. 60°. 120°. 30°. 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, 2, 5 1, 3, 5 2, 3, 4 1, 2, 3, 4 1, 2, 5 1, 3, 5 2, 3, 4 1, 2, 3, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the highest possible speed of turbo alternators? 4000 rpm 1000 rpm 1500 rpm 3000 rpm 4000 rpm 1000 rpm 1500 rpm 3000 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two synchronous generators operating in parallel 200 MW and 400 MW respectively. The drooping characteristics of their governors are identical as 4% from no load to full load. Consider the governors operating at 50Hz on no load. What is the operating frequency, if the load is 600 MW? 50 Hz 45 HZ 48.5 Hz 48 Hz 50 Hz 45 HZ 48.5 Hz 48 Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When applied rated voltage per phase is reduce to one half, the starting torque of three phase squirrel cage induction motor becomes 4 time the initial value 1/4 of the intial value 1/2 of the initial value twice the initial value 4 time the initial value 1/4 of the intial value 1/2 of the initial value twice the initial value ANSWER DOWNLOAD EXAMIANS APP
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