Electrical Machines Which of the following is done in speed control of DC motor by field flux control? Inserting an additional resistance in the field circuit. Inserting an additional resistance in the armature circuit. Any of above. Inserting resistance to armature circuit and field circuit. Inserting an additional resistance in the field circuit. Inserting an additional resistance in the armature circuit. Any of above. Inserting resistance to armature circuit and field circuit. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Direct-on-line (DOL) starters are not suitable for starting large DC motors, because the motor may run away. the motor may not start. the starting current will be enormously high. the starting torque becomes low. the motor may run away. the motor may not start. the starting current will be enormously high. the starting torque becomes low. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Compensating windings are used in DC generators to neutralize the cross magnetizing effect of the armature reaction. None of these to provide path for the circulation of cooling air. mainly to reduce the eddy currents by providing local short circuit. to neutralize the cross magnetizing effect of the armature reaction. None of these to provide path for the circulation of cooling air. mainly to reduce the eddy currents by providing local short circuit. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt generator builds up to a voltage of 220 V at no load while running at its rated speed. If the speed of the generator is raised by 25% kepping the circuit conditions unaltered, then the Voltage to which the machine would build up will increase to a value greater than 1.25 times 220 V not change and remain at 220 V increase to value lying between 220 V and 1.25 times 220 V increase to 1.25 times 220 V increase to a value greater than 1.25 times 220 V not change and remain at 220 V increase to value lying between 220 V and 1.25 times 220 V increase to 1.25 times 220 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of rotation of a 3 - Φ induction motor can be reversed by disconnecting any one phase. transposing any two leads from slip rings. transposing any two leads from supply. transposing all the three leads from the supply. disconnecting any one phase. transposing any two leads from slip rings. transposing any two leads from supply. transposing all the three leads from the supply. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Find the synchronous reactance of alternators in which a given field current of 200 A on short circuit and a generated emf of 50 V on open circuit. Armature resistance is 0.1 ohm 0.5Ω. 1Ω. 0.25Ω. 0.23Ω. 0.5Ω. 1Ω. 0.25Ω. 0.23Ω. ANSWER DOWNLOAD EXAMIANS APP
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