Electrical Machines No load test of 3-phase induction motor gives which of the following? None of these variable loss both A and B constant loss None of these variable loss both A and B constant loss ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4-pole dc generator runs at 1500 rpm. The frequencyof current in the armature winding is 25 Hz 100 Hz 0 Hz 50 Hz 25 Hz 100 Hz 0 Hz 50 Hz ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The overall power factor of an on load transformer is always leading. is always unity. is always lagging. depends on the power factor of the load. is always leading. is always unity. is always lagging. depends on the power factor of the load. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC shunt generator working on load, the brushes are moved forward in the direction of rotation, as a result of this, commutation will worsen and terminal voltage will rise. improve but terminal voltage will fall. worsen and terminal voltage will fall improve and terminal voltage will rise . worsen and terminal voltage will rise. improve but terminal voltage will fall. worsen and terminal voltage will fall improve and terminal voltage will rise . ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To control the speed of an induction motor, the supply frequency is reduced by 10%. For the same magnetizing current to remain constant, the supply voltage must be reduced by 20% increased by 10% increased by 20% reduced by 10% reduced by 20% increased by 10% increased by 20% reduced by 10% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 3 1, 2 and 3 1, 2, 3 and 4 3 only 1, 3 1, 2 and 3 1, 2, 3 and 4 3 only ANSWER DOWNLOAD EXAMIANS APP
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