A transformer transforms__________________?

The secondary winding of which of the following transformers is always kept closed?

A. Step-up transformer
B. Step-down transformer
C. Potential transformer
D. Current transformer

The no-load current drawn by transformer is usually what per cent of the full-load current ?

A. 0.2 to 0.5 per cent
B. 2 to 5 per cent
C. 12 to 15 per cent
D. 20 to 30 per cent

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

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

In a given transformer for given applied voltage, losses which remain constant irrespective of load changes are______________?

A. friction and windage losses
B. copper losses
C. hysteresis and eddy current losses
D. none of the above

Two transformers are connected in parallel. These transformers do not have equal percentage impedance. This is likely to result in____________?

A. short-circuiting of the secondaries
B. power factor of one of the transformers is leading while that of the other lagging
C. transformers having higher copper losses will have negligible core losses
D. loading of the transformers not in proportion to their kVA ratings

When secondary of a current transformer is open-circuited its iron core will be__________?

A. hot because of heavy iron losses taking place in it due to high flux density
B. hot because primary will carry heavy current
C. cool as there is no secondary current
D. none of above will happen