Electrical Machines If s is the slip and f is the supply frequency of an induction motor, the frequency of rotor current is given by sf / 2. sf. f / s. s2. sf / 2. sf. f / s. s2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A single-phase transformer has its maximum efficiency at 60 percent of full load. At full load copper loss will be zero. more than core loss. equal to core loss. less than core loss. zero. more than core loss. equal to core loss. less than core loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Why are capacitors used with large AC induction motor? Improve current level. Improve power factor. Improve power level. Improve voltage level. Improve current level. Improve power factor. Improve power level. Improve voltage level. 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 15.9 Ω 31.9 Ω 31.1 Ω 15.1 Ω 15.9 Ω 31.9 Ω 31.1 Ω 15.1 Ω 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 increase. either of these. None of these decrease. increase. either of these. None of these decrease. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Ward-Leonard system for controlling the speed of a DC motor is used where All of above. The speed in both the direction is required. Very fine speed control over the whole range from zero to normal speed is required. The accuracy in speed control is required. All of above. The speed in both the direction is required. Very fine speed control over the whole range from zero to normal speed is required. The accuracy in speed control is required. ANSWER DOWNLOAD EXAMIANS APP
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