EE_TRANSFORMER_THREE PHASE

A V-V connected transformer can be connected in parallel to delta-delta connected transformer but not to ___________

• delta-star

• star-delta

• star-V

• all of the mentioned

Three units of single phase transformers and one single three-phase transformer rating ___________

• will be same for one rating

• can never be made same

• may be same

• none of the mentioned

The transformer which is more feasible to use in the distribution ends should be ___________

• star-delta

• delta-star

• scott

• delta-delta

For the given circuit, the voltage across the terminal ‘a’ and ‘b’ is?

• 1.73*V

• V/1.73

• V

• 3*V

The voltage across the terminal ‘r’ and ‘y’ is?

• 1.73*V

• V/1.73

• V

• 3*V

The delta-delta connections are used in applications of ___________

• large l.v. transformers

• small h.v. transformers

• large h.v. transformers

• small l.v. transformers

Open delta transformers can be obtained from ___________

• delta-delta

• star-delta

• delta-star

• any of the mentioned

If one of the transformers is removed from the bank of only delta-delta, then it behaves with 58% power delivery.

• True

• False

Above is the circuit diagram for delta-delta transformer have a transformation ratio ‘k’. The current flowing in the windings of phase r-y in the below diagrams is?

• k*I/1.73

• I/k*1.73

• 1.73*k*I

• 3*k*I

If para magnetic core is used in the place of the ferromagnetic core of the transformer, then magnetostriction will ___________

• be vanished

• reduce

• increase

• not be affected