Electrical Machines which of the following losses are negligible in blocked rotor test? copper loss both A and B iron loss mechanical loss copper loss both A and B iron loss mechanical loss ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a synchronous motor electromagnetic power varies None of these directly as applied voltage inversely as applied voltage directly as square of applied voltage None of these directly as applied voltage inversely as applied voltage directly as square of applied voltage ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A separately-excited DC generator, running at rated speed, has 6 volts across its armature terminals with no field current. When field winding is excited with one ampere, the voltage builds up to 250 V at no load. In case field current is reduced to zero, with the speed remaining unaltered, the armature terminal voltage would be more than 6 V zero less than 6 V 6 V more than 6 V zero less than 6 V 6 V 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. to provide path for the circulation of cooling air. None of these mainly to reduce the eddy currents by providing local short circuit. to neutralize the cross magnetizing effect of the armature reaction. to provide path for the circulation of cooling air. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature mmf of a DC machine has triangular space distribution and is stationary in space. triangular space distribution and rotates at the speed of armature. trapezoidal space distribution and is stationary in space. stepped distribution and rotates at the speed of armature. triangular space distribution and is stationary in space. triangular space distribution and rotates at the speed of armature. trapezoidal space distribution and is stationary in space. stepped distribution and rotates at the speed of armature. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 500 V, 55 kVA single phase alternator has an effective resistance of 0.5 Ω. An excitation current of 10 A produces 200 A armature current on short circuit and an emf of 450 V on per circuit. The synchronous reactance will be 25.564 Ω. 2.781 Ω. 2.241 Ω. 2.74 Ω. 25.564 Ω. 2.781 Ω. 2.241 Ω. 2.74 Ω. ANSWER DOWNLOAD EXAMIANS APP
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