Electrical Machines For satisfactory performance of 3-phase 480V, 60 Hz induction motor, the supply voltage at 50 Hz should be equal to 400 V. 420 V. 350 V. 480 V. 400 V. 420 V. 350 V. 480 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which motor used in Lathe machine? D.C. cumulative compound motor. None of these D.C . series motor. D.C. shunt motor. D.C. cumulative compound motor. None of these D.C . series motor. D.C. shunt motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Due to magnetic saturation, the flux per pole in a DC machine without brush shift increases in generators but decreases in motor with load. decreases in generators and increases in motor with load. decreases in both generators and the motors with load. increases in both the generators and the motors with load. increases in generators but decreases in motor with load. decreases in generators and increases in motor with load. decreases in both generators and the motors with load. increases in both the generators and the motors with load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The external resistance to be added in the armature circuit to limit the armature current to 125% of its rated value is 15.1 Ω 31.1 Ω 15.9 Ω 31.9 Ω 15.1 Ω 31.1 Ω 15.9 Ω 31.9 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When applied rated voltage per phase is reduce to one half, the starting torque of three phase squirrel cage induction motor becomes 4 time the initial value 1/4 of the intial value twice the initial value 1/2 of the initial value 4 time the initial value 1/4 of the intial value twice the initial value 1/2 of the initial value 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, 6 1, 2, 5 1, 3, 5 1, 4, 6 1, 2, 6 1, 2, 5 1, 3, 5 1, 4, 6 ANSWER DOWNLOAD EXAMIANS APP
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