Electrical Machines What are slot wedges in a DC machine made of? Cast iron. Fibre. Mild steel. Silicon steel. Cast iron. Fibre. Mild steel. Silicon steel. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two synchronous generators operating in parallel 200 MW and 400 MW respectively. The drooping characteristics of their governors are identical as 4% from no load to full load. Consider the governors operating at 50Hz on no load. What is the operating frequency, if the load is 600 MW? 50 Hz 48.5 Hz 48 Hz 45 HZ 50 Hz 48.5 Hz 48 Hz 45 HZ ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes : 1 and 3 2, 3 and 4 1, 2, and 3 1, 2 and 4 1 and 3 2, 3 and 4 1, 2, and 3 1, 2 and 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In Ward-Leonard method of speed control, the direction of rotation of motor is reversed usually reversing the connection of the motor field terminal. motor armature terminal. generator field terminal. generator armature terminal. motor field terminal. motor armature terminal. generator field terminal. generator armature terminal. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Iron losses in a DC machine are independent of variation in voltage. speed and voltage. load. speed. voltage. speed and voltage. load. speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The oscillation in a synchronous motor can be damped out by providing damper bars in the rotor pole faces. running the motor on leading power factors. maintaining constant excitation. oscillation cannot be damped. providing damper bars in the rotor pole faces. running the motor on leading power factors. maintaining constant excitation. oscillation cannot be damped. ANSWER DOWNLOAD EXAMIANS APP
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