Transformers

An ideal transformer has infinite values of primary and secondary inductances. The statement is______________?

A. true
B. false

The chemical used in breather is_______________?

A. asbestos fiber
B. silica sand
C. sodium chloride
D. silica gel

The chemical used in breather for transformer should have the quality of____________?

A. ionizing air
B. absorbing moisture
C. cleansing the transformer oil
D. cooling the transformer oil

The use of higher flux density in the transformer design____________?

A. reduces weight per kVA
B. reduces iron losses
C. reduces copper losses
D. increases part load efficiency

A. primary side
B. secondary side
C. low voltage side
D. high voltage side

What will happen if the transformers working in parallel are not connected with regard to polarity ?

A. The power factor of the two trans-formers will be different from the power factor of common load
B. Incorrect polarity will result in dead short circuit
C. The transformers will not load in proportion to their kVA ratings
D. none of the above

If the percentage impedances of the two transformers working in parallel are different, then______________________?

A. transformers will be overheated
B. power factors of both the transformers will be same
C. parallel operation will be not possible
D. parallel operation will still be possible, but the power factors at which the two transformers operate will be different from the power factor of the common load

If R2 is the resistance of secondary winding of the transformer and K is the transformation ratio then the equivalent secondary resistance referred to primary will be___________?

A. R2/VK
B. R2IK2
C. R22!K2
D. R22/K

Two transformers operating in parallel will the load depending upon their____________?

A. leakage reactance
B. per unit impedance
C. efficiencies
D. ratings

The power transformer is a constant______________?

A. voltage device
B. current device
C. power device
D. main flux device