Electrical Machines What is/are the necessary conditions for voltage build up in self excited generator? Poles should contain residual flux. Field winding should be properly connected to armature winding. Field winding resistance should be less than critical resistance. All of these Poles should contain residual flux. Field winding should be properly connected to armature winding. Field winding resistance should be less than critical resistance. All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole dynamo with wave wound armature has 51 slots contains 20 conductors in each slot. If induced emf 357 Volts and speed is 8500 rpm, flux per pole will be 2.7 mWb. 1.2 mWb. 1.4 mWb. 3.5 mWb. 2.7 mWb. 1.2 mWb. 1.4 mWb. 3.5 mWb. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to over commutation. too rapid reversal of current. under commutation. any of the above. over commutation. too rapid reversal of current. under commutation. any of the above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction in DC generators will result in short circuit. open circuit. increase in slip. reduction in generated emf. short circuit. open circuit. increase in slip. reduction in generated emf. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When Flemings right hand rule to find the direction of induced emf, the thumb points towards direction of induced emf. direction of flux. opposite to the direction of motion of the conductor. direction of motion of the conductor. direction of induced emf. direction of flux. opposite to the direction of motion of the conductor. direction of motion of the conductor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the armature electric current is increased to double its previous value, and the time of commutation is halved, how will the reactance voltage vary? It will be halved. It will be doubled. It will becomes four times. It will remain the same. It will be halved. It will be doubled. It will becomes four times. It will remain the same. ANSWER DOWNLOAD EXAMIANS APP
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