Electrical Machines Which of the following alternators contain large number of poles? Hydro alternators. Aame in both alternators. Turbo alternators. None of these Hydro alternators. Aame in both alternators. Turbo alternators. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A single phase transformer has specifications as 250 KVA, 11000 V/415 V, 50 Hz. What are the values of primary and secondary currents? primary = 301 A, secondary = 22.7 A primary = 22.7 A, secondary = 602.4 A primary = 602 A, secondary = 22.7 A primary = 11.4 A, secondary = 301 A primary = 301 A, secondary = 22.7 A primary = 22.7 A, secondary = 602.4 A primary = 602 A, secondary = 22.7 A primary = 11.4 A, secondary = 301 A ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Hysteresis loss will depends on f f² f1.6 f³ f f² f1.6 f³ ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the speed control of dc motors : 1. ward-leonard method is suitable forconstant-torque drives 2. Ward-leonard method is suitable for constant-power drives 3. field-control method facilitates speed control below base speed 4. Armature-resistance control method is more efficient than ward-leanard method 5. Field-control method is suitable for constant-torque drives 6. Armature-resistance control method is suitable for constant-torque drives From these, the correct answer is 1, 2, 5 1, 3, 5 1, 2, 6 1, 4, 6 1, 2, 5 1, 3, 5 1, 2, 6 1, 4, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If s is the slip and f is the supply frequency of an induction motor, the frequency of rotor current is given by s2. sf. sf / 2. f / s. s2. sf. sf / 2. f / s. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The field system of an alternator is usually excited 110 / 220 V AC. 230 V AC. 3 - Φ, 50 Hz and 400 V. 250 / 250 V DC. 110 / 220 V AC. 230 V AC. 3 - Φ, 50 Hz and 400 V. 250 / 250 V DC. ANSWER DOWNLOAD EXAMIANS APP