Electrical Machines Considering a galvanometer is connected to the rotor of a 3 - Φ, 4 pole, 50 Hz IM and is making 130 oscillations in a minute, then calculate the rotor speed? 1450. 1440. 1500. 1435. 1450. 1440. 1500. 1435. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two mechanically coupled alternators deliver power at 50 Hz and 60 Hz respectively. The highest speed of the alternators is 600 rpm. 500 rpm. 3600 rpm. 3000 rpm. 600 rpm. 500 rpm. 3600 rpm. 3000 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum allowable tan - delta (tanδ) of dielectric dispassion factor of power transformer insulating oil is generally taken as 2 at 90°C. 3 at 90°C. 1 at 90°C. 0.5 at 90°C. 2 at 90°C. 3 at 90°C. 1 at 90°C. 0.5 at 90°C. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole wave wound dc motor having flux per pole of 9.56 X 10-3 Wb contains 460 armature conductors. Calculate the back emf produced when it is running at a speed of 1500 rpm. 240 volt. 220 volt. 230 volt. 440 volt. 240 volt. 220 volt. 230 volt. 440 volt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A large series motor is never started without some mechanical load on it because otherwise it will produce sparking at brushes. develop excessive speed and damage itself. draw too much current. open fuse or circuit breaker. produce sparking at brushes. develop excessive speed and damage itself. draw too much current. open fuse or circuit breaker. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines φA DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the speed when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 940 RPM 920 RPM 960 RPM 970 RPM 940 RPM 920 RPM 960 RPM 970 RPM ANSWER DOWNLOAD EXAMIANS APP
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