Electrical Machines At what power factor, the voltage regulation of a transformer can be zero ? Zero power factor. Leading power factor. Unity power factor. Lagging power factor. Zero power factor. Leading power factor. Unity power factor. Lagging power factor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Silicon content in steel lamination is kept within 5% as it increases hysteresis loss. Increases cost. All of these makes the material brittle. increases hysteresis loss. Increases cost. All of these makes the material brittle. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC machine, which of these parameters remain the same whether it runs as a DC motor or a DC generator? Can not be determined. Armature current. Induced emf. Mechanical power. Can not be determined. Armature current. Induced emf. Mechanical power. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements about commutating poles which are fitted on most large dc Shunt motors: 1. The commutating poles are placed in the geometric neutral plane and their number is usually Equal to the number of main poles 2. The winding on the commutating poles is connected in series with the shunt-field winding on the main poles 3. The polarity of the commutating pole must be that of the next pole further ahead 4. The commutating poles neutralize the reactance voltage produced in the coil undergoing Commutation. Of these statements, 2, 3 and 4 are correct 1 and 4 are correct 1, 2 and 4 are correct 1, 2 and 3 are correct 2, 3 and 4 are correct 1 and 4 are correct 1, 2 and 4 are correct 1, 2 and 3 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines As compared to DOL starting, a cage induction motor with star-delta starting shall have more starting torque. smoother acceleration. more starting time. reduced starting current. more starting torque. smoother acceleration. more starting time. reduced starting current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If terminal voltage of one 1000 rpm shunt motor is reduced to half the speed of the motor will be 500 rpm 1000 rpm 250 rpm 2000 rpm 500 rpm 1000 rpm 250 rpm 2000 rpm ANSWER DOWNLOAD EXAMIANS APP