Electrical Machines If the applied voltage of a certain transformer is increased by 50% and the frequency is reduced by 50%, the maximum flux density will (assuming that the magnetic circuit remains unsaturated) changes to 1.5 times the original value remain the same as the original changes to 0.5 times the original value changes to three times the original value changes to 1.5 times the original value remain the same as the original changes to 0.5 times the original value changes to three times the original value ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If s is the slip and f is the supply frequency of an induction motor, the frequency of rotor current is given by sf. f / s. s2. sf / 2. sf. f / s. s2. sf / 2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation is reduced, the power factor is None of these lagging power factor unity power factor leading power factor None of these lagging power factor unity power factor leading power factor ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following motor has the highest power factor at full load? Shaded pole Capacitor run Capacitor start Resistance split phase Shaded pole Capacitor run Capacitor start Resistance split phase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The power flow of a dc motor, with respect to a DC generator is reversed. none of these. modified. increased. reversed. none of these. modified. increased. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4-pole dc generator runs at 1500 rpm. The frequencyof current in the armature winding is 0 Hz 25 Hz 100 Hz 50 Hz 0 Hz 25 Hz 100 Hz 50 Hz ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS