NLC Technical Quiz 35

A bank of three identical single phase 250 kVA, 11 kV/230V transformer is used to provide 400V low tension supply from a 11 kV, 3 phase sub-station. The effective kVA rating of the bank will be

A synchronous machine has full-pitch coils having coil span of 12 slots for eliminating third harmonic, the coil span should be

The rotor slots are slightly skewed in squirrel-cage induction motor to

The power of a 3-phase system is measured by two-wattmeter method. The reading of both watt meters are 100 W and 200 W respectively.

Then the power factor of system will be.

A single-phase fully controlled thyristor bridge ac-dc converter is operating at a firing Angle of 30° and an overlap angle of 12° constant dc output current of 20 A .

The fundamental power factor at input ac mains is:

The speed of a three-phase wound type induction motor can be controlled by:

Buchholz’s relay is used in:

Auto transformer makes effective saving of copper and copper losses when its transformation ratio is: