Primary winding of a transformer________________?

A. Is always a low voltage winding
B. Is always a high voltage winding
C. Could either be a low voltage or high voltage winding
D. None of the above

A transformer cannot raise or lower the voltage of a D.C. supply because_______________?

A. There is no need to change the d.c. voltage
B. A d.c. circuit has more losses
C. Faraday’s laws of electromagnetic induction are not valid since the rate of change of flux is zero
D. None of the above

A transformer transforms__________________?

A. Voltage
B. Current
C. Power
D. Frequency

In the transformer following winding has got more cross-sectional area______________?

A. Low voltage winding
B. High voltage winding
C. Primary winding
D. Secondary winding

While conducting short-circuit test on a transformer the following side is short circuited?

A. High voltage side
B. Low voltage side
C. Primary side
D. Secondary side

Which of the following is not a part of transformer installation ?

A. Conservator
B. Breather
C. Buchholz relay
D. Exciter

The purpose of providing an iron core in a transformer is to_____________?

A. Provide support to windings
B. Reduce hysteresis loss
C. Decrease the reluctance of the magnetic path
D. Reduce eddy current losses

No-load current in a transformer________________?

A. Lags behind the voltage by about 75°
B. Leads the voltage by about 75°
C. Lags behind the voltage by about 15°
D. Leads the voltage by about 15°

The efficiency of a transformer will be maximum when_____________?

A. Copper losses = hysteresis losses
B. Hysteresis losses = eddy current losses
C. Eddy current losses = copper losses
D. Copper losses = iron losses

The permissible flux density in case of cold rolled grain oriented steel is around__________?

A. 1.7 wb/m2
B. 2.7 wb/m2
C. 3.7 wb/m2
D. 4.7 wb/m2