Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 2, 4 1, 4 1, 3 2, 3 2, 4 1, 4 1, 3 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two mechanically coupled alternators deliver power at 50 Hz and 60 Hz respectively. The highest speed of the alternators is 3000 rpm. 600 rpm. 500 rpm. 3600 rpm. 3000 rpm. 600 rpm. 500 rpm. 3600 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of stator rotating magnetic field (RMF) with respect to rotor is S.Ns Ns Nr Zero S.Ns Ns Nr Zero ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which one of the following statement is correct ? In an induction motor if the air gap is increased then its power factor will reduce its speed will increase its efficiency will improve its speed will reduce its power factor will reduce its speed will increase its efficiency will improve its speed will reduce ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Transformer action requires a alternating electric flux. alternating magnetic lux. constant magnetic flux. increasing magnetic flux. alternating electric flux. alternating magnetic lux. constant magnetic flux. increasing magnetic flux. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines With the increase in speed of a DC motor both back emf as well as line current fall. back emf increases but line current falls. both back emf as well as line current increase. back emf falls and line current increases. both back emf as well as line current fall. back emf increases but line current falls. both back emf as well as line current increase. back emf falls and line current increases. ANSWER DOWNLOAD EXAMIANS APP
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