Electrical Machines In speed control of DC shunt motor by varying field flux, what may be the value of field regulator? 100 ohm 2 ohm. 10 ohm 0.2 ohm 100 ohm 2 ohm. 10 ohm 0.2 ohm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following pairs is/are correct? closed slot----- leakage flux is high open slot----- leakage flux is less All of these semi closed slot-----leakage flux is moderate closed slot----- leakage flux is high open slot----- leakage flux is less All of these semi closed slot-----leakage flux is moderate 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 and 4 are correct 1, 2 and 3 are correct 1, 2 and 4 are correct 2, 3 and 4 are correct 1 and 4 are correct 1, 2 and 3 are correct 1, 2 and 4 are correct 2, 3 and 4 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Secondary winding of an auto transformer is also called damping winding. tertiary winding. compensating winding. common winding. damping winding. tertiary winding. compensating winding. common winding. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC motors are stopped by opening line switches and not by forcing the handle of the motor starter back to OFF position. This is due to occurance of Both of above. Heavy sparking at brushes. Heavy sparking at the first stud of starting resistance steps. None of these. Both of above. Heavy sparking at brushes. Heavy sparking at the first stud of starting resistance steps. None of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Direction of rotation of DC motor is reversed by Interchanging armature and field connection. Reversing supply connection. Adding resistance to field circuit. Reversing armature connection or field connection. Interchanging armature and field connection. Reversing supply connection. Adding resistance to field circuit. Reversing armature connection or field connection. ANSWER DOWNLOAD EXAMIANS APP
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