Electrical Machines If an AC servomotor has one of its winding excited by AC, then voltage measured at the other winding with rotor running will be zero. proportional to rotor speed. proportional to square of rotor speed. constant independent of speed. zero. proportional to rotor speed. proportional to square of rotor speed. constant independent of speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A short circuit test on a transformer gives copper loss at full load. copper loss at over load. copper loss at any load. copper loss at half load. copper loss at full load. copper loss at over load. copper loss at any load. copper loss at half load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the frequency of a alternator, if P = number of poles and N = revolution made per second? 120P / N Hz. 120N / P Hz. PN / 2 Hz. 120 / PN Hz. 120P / N Hz. 120N / P Hz. PN / 2 Hz. 120 / PN Hz. 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, 4, 6 1, 3, 5 1, 2, 5 1, 2, 6 1, 4, 6 1, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC generator without commutator is a DC generator DC motor AC generator induction motor DC generator DC motor AC generator induction motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor runs at a no-load speed of 1140 rpm. At full load, armature reaction weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full-load speed in rpm is 1200 1203 1080 1000 1200 1203 1080 1000 ANSWER DOWNLOAD EXAMIANS APP
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