Electrical Machines Maximum allowable tan - delta (tanδ) of dielectric dispassion factor of power transformer insulating oil is generally taken as 3 at 90°C. 0.5 at 90°C. 2 at 90°C. 1 at 90°C. 3 at 90°C. 0.5 at 90°C. 2 at 90°C. 1 at 90°C. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Short circuiting is caused in the armature winding due to failure of insulation between two commutator bars. failure of insulation between two turns of coil. grounding of two or more turns of the same coil. any of above. failure of insulation between two commutator bars. failure of insulation between two turns of coil. grounding of two or more turns of the same coil. any of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Torque developed in the rotor is directly proportional to slip not dependent on the slip either of these inversely proportional to slip directly proportional to slip not dependent on the slip either of these inversely proportional to slip ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A small air gap in poly phase induction motor helps to reduce magnetizing current. increase starting torque. reduce chance of crawling. reduce chance of cogging. reduce magnetizing current. increase starting torque. reduce chance of crawling. reduce chance of cogging. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the field winding connection of DC shunt motor is changed motor will not run. motor will become slow. It will run in same direction. It will run in opposite direction. motor will not run. motor will become slow. It will run in same direction. It will run in opposite direction. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The teeth in the armature of a DC machines are sometimes skewed. This is done to reduce hysteresis loss. eddy electric current loss. vibrations. copper loss. hysteresis loss. eddy electric current loss. vibrations. copper loss. ANSWER DOWNLOAD EXAMIANS APP