Electrical Machines If the applied voltage of a DC motor is 230 V, then back emf, for maximum power developed is 200 V. 230 V. 460 V. 115 V. 200 V. 230 V. 460 V. 115 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes : 2, 3 and 4 1, 2, and 3 1, 2 and 4 1 and 3 2, 3 and 4 1, 2, and 3 1, 2 and 4 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If in a sub – station there is one 132 / 33 kV transformer whose secondary is connected with primary of one 33 / 11 kV transformer, the total transformation ratio of the sub – station will be, 3. 12. 7. 4. 3. 12. 7. 4. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The interpoles in dc machines have a tapering shape in order to increase the acceleration of commutation economise on the material required for interpoles and their windings reduce the saturation in the interpole reduce the overall weight increase the acceleration of commutation economise on the material required for interpoles and their windings reduce the saturation in the interpole reduce the overall weight ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt generator builds up 230 V when driven in clockwise direction. In case it is driven in anti clockwise direction, other things remaining unchanged, then the voltage build up is not possible some what more than 230 V some what less than 230 V 230 V not possible some what more than 230 V some what less than 230 V 230 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The voltmeter connected across a generator reads voltage same at no load and at full load (rated). The generator is of the type series generator. short - shunt generator. level compound. shunt generator. series generator. short - shunt generator. level compound. shunt generator. ANSWER DOWNLOAD EXAMIANS APP
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