Electrical Machines A 230 V, 50 Hz, 4 pole single phase induction motor is rotating in the clockwise ( forward ) direction at a speed of 1425 rpm. If the rotor resistance at standstill is 7.8 Ω. Then the effective rotor resistance in the backward branch of the equivalent circuit will be 8 Ω. 4 Ω. 10 Ω. 2 Ω. 8 Ω. 4 Ω. 10 Ω. 2 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The interpoles in dc machines have a tapering shape in order to economise on the material required for interpoles and their windings reduce the saturation in the interpole increase the acceleration of commutation reduce the overall weight economise on the material required for interpoles and their windings reduce the saturation in the interpole increase the acceleration of commutation reduce the overall weight ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 2 pole synchronous machine is operating at 3000 rpm. Find the relation between electrical angular momentum (ωe) and mechanical angular momentum (ωm) ? ωe = 1/2*ωm ωe = ωm ωe = 2*ωm ωe = 4*ωm ωe = 1/2*ωm ωe = ωm ωe = 2*ωm ωe = 4*ωm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the field circuit of a DC shunt motor is opened The speed of motor will be reduced. The motor will attain dangerously high speed. The armature current will reduce. DC Shunt Motor The speed of motor will be reduced. The motor will attain dangerously high speed. The armature current will reduce. DC Shunt Motor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The change in speed of a DC generator due to increased load is corrected by increasing armature cooling. increasing terminal voltage. increasing input power of the prime mover. increasing armature resistance. increasing armature cooling. increasing terminal voltage. increasing input power of the prime mover. increasing armature resistance. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt generator, when driven without any excitation, showed an open circuit voltage of 12 V. When the field winding was excited, the voltage dropped to zero. It happened because there was a break in the armature circuit field resistance was higher than critical resistance field winding was wrongly connected there was no residual magnetism in the field circuit there was a break in the armature circuit field resistance was higher than critical resistance field winding was wrongly connected there was no residual magnetism in the field circuit ANSWER DOWNLOAD EXAMIANS APP
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