Electrical Machines If an additional resistance is connected in series with a DC series motor operating at rated speed, the speed of the motor will Increase. Remain unaltered. Oscillate around the normal speed. Reduce. Increase. Remain unaltered. Oscillate around the normal speed. Reduce. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the mechanical power developed by a DC series motor is maximum? Back emf is equal to half the applied voltage. None of above. Back emf is equal to zero. Back emf is equal to applied voltage. Back emf is equal to half the applied voltage. None of above. Back emf is equal to zero. Back emf is equal to applied voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt generator, when commissioned after a major repair of the field system, failed to build Up voltage. It was because field winding was wrongly connected field resistance was higher than critical resistance there was a break in the armature circuit field system lost residual magnetism field winding was wrongly connected field resistance was higher than critical resistance there was a break in the armature circuit field system lost residual magnetism ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator, the ripples in the direct emf generated are reduced by employing commutator with large number of segments. carbon brushes. equalizer rings. graphite brushes. commutator with large number of segments. carbon brushes. equalizer rings. graphite brushes. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC motor with armature resistance of 0.5 ohms is connected directly to a 230 Volt supply. If the armature is stationary then the current flowing through armature is 570 A. 250 A. 340 A. 460 A. 570 A. 250 A. 340 A. 460 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Compensating windings are used in DC generators mainly to reduce the eddy currents by providing local short circuit. to neutralize the cross magnetizing effect of the armature reaction. None of these to provide path for the circulation of cooling air. mainly to reduce the eddy currents by providing local short circuit. to neutralize the cross magnetizing effect of the armature reaction. None of these to provide path for the circulation of cooling air. ANSWER DOWNLOAD EXAMIANS APP
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