Electrical Machines In DC machine torque depends on which of the following? flux (φ) speed both A and B armature current (I) flux (φ) speed both A and B armature current (I) ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To avoid formation of grooves in the commutator the brushes of opposite polarity should track each other. None of these brush position has no effect on the commutator grooving. the brushes of same polarity should track each other. the brushes of opposite polarity should track each other. None of these brush position has no effect on the commutator grooving. the brushes of same polarity should track each other. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor runs at a no-load speed of 1140 rpm. At full load, armature reaction weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full-load speed in rpm is 1203 1080 1200 1000 1203 1080 1200 1000 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The fall in speed of the DC generator due to increase in load can be corrected by increasing the excitation. reducing the load voltage. increasing the input to the prime mover. cooling the armature. increasing the excitation. reducing the load voltage. increasing the input to the prime mover. cooling the armature. 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 , 3, 5 1, 4,5 2, 4, 5 2, 3, 5 1 , 3, 5 1, 4,5 2, 4, 5 2, 3, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Direction of rotation of DC motor is reversed by Reversing armature connection or field connection. Reversing supply connection. Interchanging armature and field connection. Adding resistance to field circuit. Reversing armature connection or field connection. Reversing supply connection. Interchanging armature and field connection. Adding resistance to field circuit. ANSWER DOWNLOAD EXAMIANS APP
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