Electrical Machines In a three phase star - delta transformer, what is the angle difference between primary and secondary phase voltages? Star side lags by -30°. Delta side lags by -30°. Delta side leads by 30°. Star side leads by 30°. Star side lags by -30°. Delta side lags by -30°. Delta side leads by 30°. Star side leads by 30°. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the mechanical power developed by a DC series motor is maximum? None of above. Back emf is equal to half the applied voltage. Back emf is equal to zero. Back emf is equal to applied voltage. None of above. Back emf is equal to half the applied voltage. Back emf is equal to zero. Back emf is equal to applied voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the rotor speed, in a synchronous machine, becomes more than the synchronous speed during hunting, the damper bars develop induction motor torque. induction generator torque. DC motor torque. synchronous motor torque. induction motor torque. induction generator torque. DC motor torque. synchronous motor torque. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature reaction effect is more in which of the following methods? armature resistance control same in both methods field weakening method None of these armature resistance control same in both methods field weakening method None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The power factor of an induction motor operating at no load will have a value around unity 0.2 lead 0.9 lag 0.2 lag unity 0.2 lead 0.9 lag 0.2 lag ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor is running with a divertor connected across its field winding. If the divertor resistance is reduced then the speed of the motor will decrease. increase. become execessively high. remain unaltered. decrease. increase. become execessively high. remain unaltered. ANSWER DOWNLOAD EXAMIANS APP
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