Electrical Machines If any two leads from slip rings are interchanged in a 3 - Φ induction motor, the motor will continue running in the same direction as before. not run. run in a direction opposite to previous one. get damaged. continue running in the same direction as before. not run. run in a direction opposite to previous one. get damaged. 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, 1, 2 and 3 are correct 1, 2 and 4 are correct 1 and 4 are correct 2, 3 and 4 are correct 1, 2 and 3 are correct 1, 2 and 4 are correct 1 and 4 are correct 2, 3 and 4 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following windings are necessary in case of all dc machines? closed winding lap winding open type winding wave winding closed winding lap winding open type winding wave winding ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What does happen if tripled harmonics given to induction motor? Fail to start. Nothing will happen. Will results in open circuit. Will results in short circuit. Fail to start. Nothing will happen. Will results in open circuit. Will results in short circuit. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines which of the following losses are negligible in blocked rotor test? copper loss mechanical loss both A and B iron loss copper loss mechanical loss both A and B iron loss ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Width of a carbon brush should be equal to the width of the 1 to 2 commutator segment. the width of the 2 to 3 commutator segment. less than the width of commutator segment. the width more than 3 commutator segment. the width of the 1 to 2 commutator segment. the width of the 2 to 3 commutator segment. less than the width of commutator segment. the width more than 3 commutator segment. ANSWER DOWNLOAD EXAMIANS APP