Machine Ratings Objective Questions
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For a single phase, 50 Hz transformer, if the open circuit test is conducted at 40 Hz. What is the variation in the noload power factor of the transformer?
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A 200V, 10 hp, 4 poles, 60 Hz, Yconnected induction motor had full load slip of 5%. Then the rotor speed of the motor with respect to stator is
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Auto transformer rating is chosen so as to have best performance, when the analogous two winding transformer has
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The desired voltage regulation for a single phase, 50 Hz transformer is zero. Its pu ohmic drop is 4% and pu reactive drop is 4%. The required power factor angle for the operation in degrees
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For a separately excited dc machine of 25 kW, 250 V and armature resistance of 0.25 ohms, is running at 3000 rpm with supply of 255 V.
The electromagnetic power produced at the armature in kilo watts is
The electromagnetic power produced at the armature in kilo watts is
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In the lab, two students X and Y conducted the experiments to verify the name plate ratings of the transformer.But student X conducted the same at higher frequency. The kVA reading of student X will be
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While conducting lab experiments on DC machine loading, the students are given a machine with its rating as 100 kW maximum rating. Then
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Refer the diagram; a singlephase supply of 100V, 50Hz is fed to the stepup transformer having primary impedance of 1 ohms and secondary impedance 20 ohms. What is the power consumed by the load of 5 ohms
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If the dimension of a single phase transformer is made sqrt(3) times less than the original structure,then what is new no load current rating of the transformer?
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A 3phase, five limbed shell type transformer, star connected, 200V, 50 Hz, 100 kVA will have
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If two alternators A and B are operated in parallel having per unit synchronous reactance as 0.02 ohms and 0.05 ohms respectively.Then what the ratio of contributing loading of machine A to B?
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