Electrical Machines Eb/Vt ratio of a DC motor is an indication of efficiency. starting torque. running torque. speed regulation. efficiency. starting torque. running torque. speed regulation. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the necessity of copper brushes in a dc motors? To absorb the mechanical shocks produced during running condition. To convert alternating supply current to direct current. None of these. To increase the flux cutting by the rotor. To absorb the mechanical shocks produced during running condition. To convert alternating supply current to direct current. None of these. To increase the flux cutting by the rotor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in DC generators will result in open circuit. increase in slip. short circuit. reduction in generated emf. open circuit. increase in slip. short circuit. reduction in generated emf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be 48.0%. 59.2%. 88.8%. 57.1%. 48.0%. 59.2%. 88.8%. 57.1%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The current drawn by the armature of DC motor is directly proportional to None of above. The torque required. The speed of motor. The voltage across the terminals. None of above. The torque required. The speed of motor. The voltage across the terminals. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Sparkless commutation can be achieved by employing inter poles. high resistance carbon brushes. compensating winding. any one or more of the above methods. inter poles. high resistance carbon brushes. compensating winding. any one or more of the above methods. ANSWER DOWNLOAD EXAMIANS APP
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