Electrical Machines In a 3 - φ induction motor running at full load which of these parameters is stationary with respect to the stator mmf wave? Both rotor and stator winding. Stator winding. Rotor mmf wave. Rotor winding. Both rotor and stator winding. Stator winding. Rotor mmf wave. Rotor winding. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What type of dielectric material is used in capacitors used for fans and for power factor correction? Mica. Glass. Oil impregnated paper. Vacuum. Mica. Glass. Oil impregnated paper. Vacuum. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 230 V, 50 Hz, 4 pole single phase induction motor is rotating in the clockwise ( forward ) direction at a speed of 1425 rpm. If the rotor resistance at standstill is 7.8 Ω. Then the effective rotor resistance in the backward branch of the equivalent circuit will be 8 Ω. 10 Ω. 2 Ω. 4 Ω. 8 Ω. 10 Ω. 2 Ω. 4 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes : 2, 3 and 4 1, 2 and 4 1, 2, and 3 1 and 3 2, 3 and 4 1, 2 and 4 1, 2, and 3 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The squirrel cage induction motors are provided with blades in order to facilitate cooling of rotor. none of these. balance the rotor dynamically. eliminate noise. facilitate cooling of rotor. none of these. balance the rotor dynamically. eliminate noise. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation of the synchronous generator fails, it acts as a/an induction motor. synchronous motor. induction generator. synchronous generator. induction motor. synchronous motor. induction generator. synchronous generator. ANSWER DOWNLOAD EXAMIANS APP
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