Electrical Machines What is the necessity of copper brushes in a dc motors? To convert alternating supply current to direct current. None of these. To absorb the mechanical shocks produced during running condition. To increase the flux cutting by the rotor. To convert alternating supply current to direct current. None of these. To absorb the mechanical shocks produced during running condition. To increase the flux cutting by the rotor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The torque speed characteristics of a AC servomotor is approximately any of the above hyperbola parabola linearised any of the above hyperbola parabola linearised ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor has external resistance Ra and Rf in the armature and field circuits respectively. Armature current at starting can be reduced by keeping Ra maximum and Rf maximum Ra maximum and Rf minimum Ra minimum and Rf minimum Rf maximum and Ra minimum Ra maximum and Rf maximum Ra maximum and Rf minimum Ra minimum and Rf minimum Rf maximum and Ra minimum ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A synchorous generator connected to an infinite bus is over excited. Considering only the reactive power from the point view of the system the machine acts as A resistor. None of these. A capacitor. an inductor. A resistor. None of these. A capacitor. an inductor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a DC machine having P no of pole pairs Z no of conductors having length L of resistivity ρ and cross section S are arranged. what is the armature resistance for lap-winding ? PZL/4S PZL/4Sa² PZL/4SP² PZL/ 4Sa PZL/4S PZL/4Sa² PZL/4SP² PZL/ 4Sa ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A voltmeter gives 120 oscillations per minute when connected to the rotor of an induction motor. The frequency is 50Hz. The slip of the motor is 5% 25% 4% 2% 5% 25% 4% 2% ANSWER DOWNLOAD EXAMIANS APP
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