Electrical Machines Two mechanically coupled alternators deliver power at 50 Hz and 60 Hz respectively. The highest speed of the alternators is 3600 rpm. 500 rpm. 3000 rpm. 600 rpm. 3600 rpm. 500 rpm. 3000 rpm. 600 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Find the synchronous reactance of alternators in which a given field current of 200 A on short circuit and a generated emf of 50 V on open circuit. Armature resistance is 0.1 ohm 1Ω. 0.5Ω. 0.23Ω. 0.25Ω. 1Ω. 0.5Ω. 0.23Ω. 0.25Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ induction motor draws an current of 50 A from mains when starts by direct switching. If an auto transformer with 60 % tapping is used for starting the current drawn from the mains will be 36. 18. 50. 80. 36. 18. 50. 80. 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 1, 2, 3, 4 2, 3, 4 1, 2, 5 1, 3, 5 1, 2, 3, 4 2, 3, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the field circuit of a DC shunt motor is opened The speed of motor will be reduced. The motor will attain dangerously high speed. The armature current will reduce. DC Shunt Motor The speed of motor will be reduced. The motor will attain dangerously high speed. The armature current will reduce. DC Shunt Motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator, the armature reaction results in demagnetization of centers of poles. magnetization of leading and demagnetization of trailing pole tip. demagnetization of leading & magnetization of trailing pole tip. magnetization of inter poles. demagnetization of centers of poles. magnetization of leading and demagnetization of trailing pole tip. demagnetization of leading & magnetization of trailing pole tip. magnetization of inter poles. ANSWER DOWNLOAD EXAMIANS APP