Electrical Machines A transformer has maximum efficiency at 3/4 load. The ratio of iron loss and full load copper loss is 3/4. 9/16. 16/9. 4/3. 3/4. 9/16. 16/9. 4/3. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines To control the speed of an induction motor, the supply frequency is reduced by 10%. For the same magnetizing current to remain constant, the supply voltage must be reduced by 10% reduced by 20% increased by 10% increased by 20% reduced by 10% reduced by 20% increased by 10% increased by 20% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In field flux method speed control of DC Motor is constant torque drive below the base speed. constant torque drive above the base speed. constant power drive above base speed. constant hp drive below the base speed. constant torque drive below the base speed. constant torque drive above the base speed. constant power drive above base speed. constant hp drive below the base speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 2, 4 1, 3 2, 3 1, 4 2, 4 1, 3 2, 3 1, 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A voltmeter gives 120 oscillations per minute when connected to the rotor of an induction motor. The frequency is 50Hz. The slip of the motor is 25% 4% 5% 2% 25% 4% 5% 2% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the excitation of the synchronous generator fails, it acts as a/an induction generator. synchronous generator. synchronous motor. induction motor. induction generator. synchronous generator. synchronous motor. induction motor. ANSWER DOWNLOAD EXAMIANS APP
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