Electrical Machines The heat transfer by convection in a transformer least depends on air velocity. temperature difference. surface area. color of the paint. air velocity. temperature difference. surface area. color of the paint. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is/are the advantages of carbon brush over the copper brush? In case of any sparking they will be less damaged than copper brushes They are not hard as copper brush They are self lubricating in nature All of these In case of any sparking they will be less damaged than copper brushes They are not hard as copper brush They are self lubricating in nature All of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole 50 Hz 1-phase induction motor is running at 1470 rpm. Find the forward and backward slips? 0.02, 0.98 0.04, 0.96 0.04, 1.96 0.02, 1.98 0.02, 0.98 0.04, 0.96 0.04, 1.96 0.02, 1.98 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a dc machine, 1. physically, the brush axis is along the direct axis 2. physically, the brush axis is along the interpolar axis 3. schematically, the brush axis is along the direct axis 4. schematically, the brush axis is along the quadrature axis 5. armaturemmf is directed along the brush axis From these, the correct statements are 1, 4,5 2, 4, 5 2, 3, 5 1 , 3, 5 1, 4,5 2, 4, 5 2, 3, 5 1 , 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The brushes of a DC machine should be placed on the armature in the polar axis. commutator in the inter polar axis. armature midway between poles. commutator in the polar axis. armature in the polar axis. commutator in the inter polar axis. armature midway between poles. commutator in the polar axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a DC machine having P no of pole pairs, Z no of conductors having length L of resistivity ρ and cross section S are arranged. what is the armature resistance for simple wave-winding ? PZL/4Sa² PZL/4Sp² PZL/ 4Sa PZL/4S PZL/4Sa² PZL/4Sp² PZL/ 4Sa PZL/4S ANSWER DOWNLOAD EXAMIANS APP