Electrical Machines In dc machines, the space distribution of air-gap flux density wave at no load is rectangular co- sinusoidal sinusoidal flat-topped rectangular co- sinusoidal sinusoidal flat-topped ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If an additional resistance is connected in series with a DC motor operating at rated speed, the speed of the motor will Oscillate around the normal speed. Increase. Reduce. Remain unaltered. Oscillate around the normal speed. Increase. Reduce. Remain unaltered. 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, 2, 6 1, 3, 5 1, 4, 6 1, 2, 5 1, 2, 6 1, 3, 5 1, 4, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor speed of an induction motor is given by None of these Ns = 120f /p × ( 1 - r). Ns = 120f / p × ( 1 - s ). Nr = 120f / p × (1-s). None of these Ns = 120f /p × ( 1 - r). Ns = 120f / p × ( 1 - s ). Nr = 120f / p × (1-s). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Variation in speed by ward-Leonard control of DC motors occurs due to variation in Armature current. Armature voltage. Field excitaion. Supply voltage. Armature current. Armature voltage. Field excitaion. Supply voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Capacitor in split phase induction motor is used to improve the starting torque. reduce the harmonics. improve the power factor. start the motor. improve the starting torque. reduce the harmonics. improve the power factor. start the motor. ANSWER DOWNLOAD EXAMIANS APP
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