Electrical Machines In travelling cranes for hoisting and lowering which type of motor is preferred? Single phase induction motor. DC series motor. AC slip ring motor. Synchronous motor. Single phase induction motor. DC series motor. AC slip ring motor. Synchronous motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Fifth harmonic component of the induced voltage in three phase AC generator can be eliminated by using a winding pitch of 6 / 7. 5 / 6. 2 / 3. 4 / 5. 6 / 7. 5 / 6. 2 / 3. 4 / 5. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Slip test is performed to determine positive sequence reactance and negative sequence reactance slip All of these direct axis reactance and quadrature axis reactance positive sequence reactance and negative sequence reactance slip All of these direct axis reactance and quadrature axis reactance ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Interpoles in a DC motor must be Series excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. Series excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the ahead main pole in the direction of rotation of armature. Shunt excited and should have the same polarity as that of the behind main pole in the direction of rotation of armature. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Iron loss in a transformer mainly occurs in winding of transformer. transformer insulating oil. iron made tank of transformer. steel core in transformer. winding of transformer. transformer insulating oil. iron made tank of transformer. steel core in transformer. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 82.5% 72.5% 78.5% 67.5% 82.5% 72.5% 78.5% 67.5% ANSWER DOWNLOAD EXAMIANS APP