Electrical Machines Maximum allowable acidity level of power transformer insulating oil is generally taken as 1 mg of KOH / gm. 2 mg of KOH / gm. 0.3 mg of KOH / gm. 0.5 mg of KOH / gm. 1 mg of KOH / gm. 2 mg of KOH / gm. 0.3 mg of KOH / gm. 0.5 mg of KOH / gm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The constant losses in transformer is/are eddy current loss. both 2 and 3. hysteresis loss. copper loss. eddy current loss. both 2 and 3. hysteresis loss. copper loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motor has negative speed regulation? Differential compound motor Cumulative compound motors Series motor Shunt motor Differential compound motor Cumulative compound motors Series motor Shunt motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3-phase slip ring induction motor is wound for 4 poles on stator and 6 poles on the rotor. When 3-phase balanced voltage source at 50 Hz is applied, it will run at 750rpm zero speed 1500 rpm 1000 rpm 750rpm zero speed 1500 rpm 1000 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The no load and full load speed of DC mototr are 1400 rpm and 1200 rpm respectively. What is the percentage speed regulation of the motor? 15.30%. 16.67%. 14.28%. 18.25%. 15.30%. 16.67%. 14.28%. 18.25%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes : 1, 2, and 3 2, 3 and 4 1, 2 and 4 1 and 3 1, 2, and 3 2, 3 and 4 1, 2 and 4 1 and 3 ANSWER DOWNLOAD EXAMIANS APP