Electrical Machines For a 3-phase, 4 pole, 50 Hz synchronous motor the frequency, pole number and the frequency are halved. The motor speed will be 375 rpm 3000 rpm 75 rpm 1500 rpm 375 rpm 3000 rpm 75 rpm 1500 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC motors are stopped by opening line switches and not by forcing the handle of the motor starter back to OFF position. This is due to occurance of Heavy sparking at brushes. Heavy sparking at the first stud of starting resistance steps. Both of above. None of these. Heavy sparking at brushes. Heavy sparking at the first stud of starting resistance steps. Both of above. None of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following machine will have maximum efficiency? DC motor. Electrical power generator. Electrical power transformer. Induction motor. DC motor. Electrical power generator. Electrical power transformer. Induction motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of DC Shunt Motor electromagnetic torque developed is 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. Proportional to the square of armature current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A three phase 400 V, 6 pole, 50 Hz, squirrel cage induction motor is running at a slip of 5%. The speed of stator magnetic field with respect to rotor magnetic field and speed of rotor w.r.t stator magnetic field are 1000 rpm, - 50 rpm. 1000 rpm, 950 rpm. zero, 950 rpm. zero , - 50 rpm. 1000 rpm, - 50 rpm. 1000 rpm, 950 rpm. zero, 950 rpm. zero , - 50 rpm. ANSWER DOWNLOAD EXAMIANS APP
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. 0.573. 0.512. 0.443. 0.649. 0.573. 0.512. 0.443. 0.649. ANSWER DOWNLOAD EXAMIANS APP
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