A. protects the primary circuit

B. is safe to human beings

C. none of the above

A. a D.C. circuit has more losses

B. none of the above

D. there is no need to change the D.C. voltage

B. less than one

C. none of the above

D. great than one

B. Overfluxing protection

C. Overcurrent protection

D. All of the above

B. zero

C. unity

D. lagging

A. core losses

B. hysteresis losses

C. eddy current losses

B. none of the above

C. inductive only

D. inductive or resistive

A. current and voltage

C. voltage

D. current

A. on zero power factor

B. on overload

C. on full-load

A. Potential transformer

B. Step-down transformer

C. Step-up transformer

B. high voltage side of small capacity transformers

C. high frequency transformers

D. high voltage side of high kVA rating transformers

B. much smaller

C. about the same

D. somewhat smaller

E. none of the above

A. 4 mm to 5 mm

B. 14 mm to 15 mm

D. 25 mm to 40 mm

A. copper core

B. cost iron core

D. mild steel core

A. none of the above

C. special test

D. routine test

B. Conservator

C. Buchholz relay

D. Breather

A. Voltage

B. All of the above

C. Current

A. hysteresis losses = eddy current losses

B. copper losses = hysteresis losses

C. eddy current losses = copper losses

A. load changes

C. oil in the transformer

D. mechanical vibrations

A. 50% full load

C. 70% full load

D. no load

B. not change

C. any of the above

D. decrease

B. average value

C. instantaneous value

D. r.m.s. value

A. Its secondary voltage is 400 V

B. Its rating is 2 kVA

C. Its secondary current is 5 A

D. It is a step-up transformer

A. its power factor will be zero

B. its power factor will remain unaffected

D. its power factor will increase

A. to cool the transformer oil

C. to provide oxygen inside the tank

D. to cool the coils during reduced load

A. copper winding

B. transformer tank

D. frame or case

E. iron core

A. kW

B. volts

C. amperes

B. hysteresis losses

C. copper losses

D. eddy current losses

A. none of the above

C. through cooling coil

D. through air

A. asbestos fiber

B. silica sand

D. sodium chloride

A. core flux density is reduced

C. iron losses are reduced

D. flux density remains unaffected

A. provide support to windings

C. reduce eddy current losses

D. reduce hysteresis loss

B. electrical fault outside the transformer in outgoing feeder

C. for both outside and inside faults

D. none of the above

A. none of the above

B. The power factor of the two trans-formers will be different from the power factor of common load

C. The transformers will not share load in proportion to their kVA ratings