Electrical Machines The frequency of voltage generated by an alternator having 8 poles and rotating at 250 rpm is 50 Hz. 16.67 Hz. 60 Hz. 25 Hz. 50 Hz. 16.67 Hz. 60 Hz. 25 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motor has the highest power factor at full load? Capacitor start Shaded pole Resistance split phase Capacitor run Capacitor start Shaded pole Resistance split phase Capacitor run 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 1500 rpm zero speed 1000 rpm 750rpm 1500 rpm zero speed 1000 rpm 750rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In V/f speed control of 3-phase induction motor, with increase in frequency, the slip at which maximum torque occurs None of these decrease. increase. either of these. None of these decrease. increase. either of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A commutator in DC machines can 1. provide half-wave rectification 2. Provide full-wave rectification 3. convert ac to dc 4. Convert dc to ac 5. provide controlled full-wave rectification From these, the correct answer is 2, 3, 4, 5 2, 3, 4 1, 2, 3 2, 3 ,5 2, 3, 4, 5 2, 3, 4 1, 2, 3 2, 3 ,5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole dynamo with wave wound armature has 51 slots contains 20 conductors in each slot. If induced emf 357 Volts and speed is 8500 rpm, flux per pole will be 1.4 mWb. 1.2 mWb. 3.5 mWb. 2.7 mWb. 1.4 mWb. 1.2 mWb. 3.5 mWb. 2.7 mWb. ANSWER DOWNLOAD EXAMIANS APP