Electrical Machines In a transformer zero voltage regulation is achieved at a load power factor which is zero lagging leading unity zero lagging leading unity 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, 4, 6 1, 3, 5 1, 2, 6 1, 2, 5 1, 4, 6 1, 3, 5 1, 2, 6 1, 2, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A synchronous machine has P number of poles, find the relation between electrical angular momentum (ωe) and mechanical angular momentum (ωm)? ωe = P/2*ωm ωe = 2/P*ωm ωe = ωm ωe = P*ωm ωe = P/2*ωm ωe = 2/P*ωm ωe = ωm ωe = P*ωm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : Interpoles in dc machines 1. reducearmature reaction effects in the interpolar region 2. have the same dimension as main polls 3. have their windings connected in series with the armature 4. have same number of turns as the armature 5. have the polarity same as that of the main pole ahead in a motor From these, the correct statements are 1 and 3 1, 3 and 5 1, 2 and 3 1, 2, 3 and 5 1 and 3 1, 3 and 5 1, 2 and 3 1, 2, 3 and 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor of a three phase induction motor has an impedance of 0.4 + j4 ohm per phase at standstill the maximum torque occurs at a slip of _____________. 25 %. 15 %. 50 %. 10 %. 25 %. 15 %. 50 %. 10 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Speed of DC motor can be controlled by varying applied voltage. all of these. resistance of armature culture. its flux oer pole. applied voltage. all of these. resistance of armature culture. its flux oer pole. ANSWER DOWNLOAD EXAMIANS APP