Electrical Machines A commutator with a diameter of 50 cm rotating at 1000 rpm. For a brush width of 1.5 cm, find the time of commutation in ms. 0.512. 0.573. 0.649. 0.443. 0.512. 0.573. 0.649. 0.443. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motor is expensive for same Kw output rates? Induction motor. Synchronous motor. AC single phase motor. DC Shunt Motor Induction motor. Synchronous motor. AC single phase motor. DC Shunt Motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of DC Shunt Motor electromagnetic torque developed is Proportional to the square of armature current. None of above. Proportional to the armature current. Inversely proportional to the armature current. Proportional to the square of armature current. None of above. Proportional to the armature current. Inversely proportional to the armature current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt generator, when driven without any excitation, showed an open circuit voltage of 12 V. When the field winding was excited, the voltage dropped to zero. It happened because field resistance was higher than critical resistance field winding was wrongly connected there was a break in the armature circuit there was no residual magnetism in the field circuit field resistance was higher than critical resistance field winding was wrongly connected there was a break in the armature circuit there was no residual magnetism in the field circuit ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Oil is provided in an oil filled transformer for lubrication. insulating. both cooling and insulation. cooling. lubrication. insulating. both cooling and insulation. cooling. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a transformer which of the following losses are zero? Rotational loss Copper loss All of these Iron loss Rotational loss Copper loss All of these Iron loss ANSWER DOWNLOAD EXAMIANS APP