Electrical Machines Addition of 0.3 % to 4.5 % silicon to iron increases the hysteresis loss. None of these increases the electrical resistivity of iron. reduces the saturation magnetization. increases the hysteresis loss. None of these increases the electrical resistivity of iron. reduces the saturation magnetization. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a dc machine shunt resistance and armature resistance values are low and low low and high high and low high and high low and low low and high high and low high and high ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator sparking between brushes and commutator surface may be due to under commutation. too rapid reversal of current. over commutation. any of the above. under commutation. too rapid reversal of current. over commutation. any of the above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature resistance control method is used for the _______ ? both 1 and 2 above rated speed below rated speed None of these both 1 and 2 above rated speed below rated speed None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a step down transformer which one of the following statements is true? Secondary power is less than primary power. Number of secondary turns is more than that of primary. Number of secondary turns is less than primary turns. Secondary current is less than primary current. Secondary power is less than primary power. Number of secondary turns is more than that of primary. Number of secondary turns is less than primary turns. Secondary current is less than primary current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The brush-axis of a bipolar dc motor is rotated by 90°. The effect of this rotation on the back emf Eband the torque developed Tdwould be such that Eb is unchanged, but Td is zero both Eb and Td are zero Eb is zero, but Td is unchanged both Eb and Td are unchanged Eb is unchanged, but Td is zero both Eb and Td are zero Eb is zero, but Td is unchanged both Eb and Td are unchanged ANSWER DOWNLOAD EXAMIANS APP