Electrical Machines A 240 V DC series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 ohms. The value of resistance which must be added to obtain rated torque at 1000 rpm is 5.7 ohms. 2.2 ohms. 1.9 ohms. 6 ohms. 5.7 ohms. 2.2 ohms. 1.9 ohms. 6 ohms. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Armature resistance control method is used for the _______ ? both 1 and 2 above rated speed None of these below rated speed both 1 and 2 above rated speed None of these below rated speed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the air gap of IM is increased, ____________ will increase. air gap flux. power factor. magnetizing current. speed. air gap flux. power factor. magnetizing current. speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Current in a coil undergoing commutation is not able to get reversed completely by the end of commutation period. It is due to None of these coil resistance. armature emf. reactance voltage induced in the coil. None of these coil resistance. armature emf. reactance voltage induced in the coil. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 250 volt dc series motor having an armature resistance of 0.2 Ω takes a load current of 60 A. What will be the torque produced at the shaft of the motor? Consider brush drop of 1V. 133.22 N-m 266.20 N-m. 234.76 N-m. can not be determined. 133.22 N-m 266.20 N-m. 234.76 N-m. can not be determined. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following statements is/are correct statements? All of these EMF per turn in HV winding is less than EMF per turn in LV winding EMF per turn in HV winding is more than EMF per turn in LV winding EMF per turn in both the windings are equal All of these EMF per turn in HV winding is less than EMF per turn in LV winding EMF per turn in HV winding is more than EMF per turn in LV winding EMF per turn in both the windings are equal ANSWER DOWNLOAD EXAMIANS APP