Electrical Machines If the handle of a three point starter goes to back to OFF position, it may be due to over load. high filed circuit resistance. zero or very low voltage supply. all of these. over load. high filed circuit resistance. zero or very low voltage supply. all of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following machine is invariably provided with forced ventilation? Hermetically sealed motor of refrigerator. Fractional horse power high speed motor. 50 MW generator in a power plant. Fractional horse power slow speed motor. Hermetically sealed motor of refrigerator. Fractional horse power high speed motor. 50 MW generator in a power plant. Fractional horse power slow speed motor. 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 : 1, 2, and 3 2, 3 and 4 1 and 3 1, 2 and 4 1, 2, and 3 2, 3 and 4 1 and 3 1, 2 and 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Hysteresis loss will depends on f f² f³ f1.6 f f² f³ f1.6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following represents the pitch factor? sin (α/2) Cos (α/2) Cos α² Cos α sin (α/2) Cos (α/2) Cos α² Cos α 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, 3, 5 1, 2, 6 1, 4, 6 1, 2, 5 1, 3, 5 1, 2, 6 1, 4, 6 1, 2, 5 ANSWER DOWNLOAD EXAMIANS APP
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