Electrical Machines Oil is provided in an oil filled transformer for both cooling and insulation. cooling. insulating. lubrication. both cooling and insulation. cooling. insulating. lubrication. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : 1. interpole windings are connected in series with armature windings 2. polarity of interpoles must be the same as that of the main poles in advance 3. distortion of the main field under the pole shoes is not affected by the use of interpoles From above, the correct answer is 1 alone 1 and 2 1 and 3 2 and 3 1 alone 1 and 2 1 and 3 2 and 3 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. None of these decrease. either of these. increase. None of these decrease. either of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The mechanical power is developed by a DC motor is maximum when back emf is equal to half of applied voltage. back emf is equal to applied voltage. back emf is equal to twice of applied voltage. none of above. back emf is equal to half of applied voltage. back emf is equal to applied voltage. back emf is equal to twice of applied voltage. none of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following machines have highest power factor with respect to magnetizing current? Open slot type machines. Any of the above. Closed slot type machines. Semi closed slot type machine. Open slot type machines. Any of the above. Closed slot type machines. Semi closed slot type machine. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The main disadvantage(s) of the ward-Leonard system is/are high maintenance cost. high initial cost. poor overall efficiency. all of above. high maintenance cost. high initial cost. poor overall efficiency. all of above. ANSWER DOWNLOAD EXAMIANS APP