Electrical Machines A 3- phase synchronous motor can operate over a wide range of power factors i.e. from lagging to leading power factor. This is achieved by varying the applied voltage. changing the field excitation. changing the load. varying the speed. varying the applied voltage. changing the field excitation. changing the load. varying the speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The main disadvantage(s) of the ward-Leonard system is/are high initial cost. all of above. poor overall efficiency. high maintenance cost. high initial cost. all of above. poor overall efficiency. high maintenance cost. 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 4 1, 2, and 3 1 and 3 2, 3 and 4 1, 2 and 4 1, 2, and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In shaded pole induction motors, the flux moves from ------------- region to ----------------- region respectively? unshaded, unshaded shaded, shaded unshaded, shaded shaded, unshaded unshaded, unshaded shaded, shaded unshaded, shaded shaded, unshaded ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If a DC Series motor is connected across an AC supply it will run at normal speed. run at lower speed. burn. not run. run at normal speed. run at lower speed. burn. not run. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The ___________________ generator has the poorest voltage regulation. differential compounded. under-compounded. over compounded. shunt. differential compounded. under-compounded. over compounded. shunt. ANSWER DOWNLOAD EXAMIANS APP