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. s2. sf. f / s. sf / 2. s2. sf. f / s. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum allowable tan - delta (tanδ) of dielectric dispassion factor of power transformer insulating oil is generally taken as 3 at 90°C. 1 at 90°C. 2 at 90°C. 0.5 at 90°C. 3 at 90°C. 1 at 90°C. 2 at 90°C. 0.5 at 90°C. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of DC Shunt Motor, the speed will____ if the voltage increases, neglecting armature saturation. remain the same. decrease. increase be unpredictable. remain the same. decrease. increase be unpredictable. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V DC series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 ohms. The value of resistance which must be added to obtain rated torque at 1000 rpm is 6 ohms. 2.2 ohms. 5.7 ohms. 1.9 ohms. 6 ohms. 2.2 ohms. 5.7 ohms. 1.9 ohms. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor speed of an induction motor is given by Ns = 120f / p × ( 1 - s ). Ns = 120f /p × ( 1 - r). Nr = 120f / p × (1-s). None of these Ns = 120f / p × ( 1 - s ). Ns = 120f /p × ( 1 - r). Nr = 120f / p × (1-s). None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators brushes are used for collecting of current without any sparkings reduce eddy current loss collecting of voltage convert ac armature current in to dc collecting of current without any sparkings reduce eddy current loss collecting of voltage convert ac armature current in to dc ANSWER DOWNLOAD EXAMIANS APP
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