No-load current in a transformer________________?

Related Mcqs:

1. 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

2. 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

3. In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of_________________?

   A. less than 15 A
   B. more than 15 A
   C. 15 A
   D. none of the above

4. The full-load copper loss of a trans¬former is 1600 W. At half-load, the copper loss will be___________?

   A. 6400 W
   B. 1600 W
   C. 800 W
   D. 400 W

5. In an actual transformer the iron loss remains practically constant from no load to full load because:____________?

   A. value of transformation ratio remains constant
   B. permeability of transformer core remains constant
   C. core flux remains practically constant
   D. primary voltage remains constant
   C. secondary voltage remains constant

6. The no load current in a transformer lags behind the applied voltage by an angle of about_____________?

   A. 180°
   B. 120″
   C. 90°
   D. 75°

7. No-load current of a transformer has_____________?

   A. has high magnitude and low power factor
   B. has high magnitude and high power factor
   C. has small magnitude and high power factor
   D. has small magnitude and low power factor

8. For a transformer, operating at constant load current, maximum efficiency will occur at______________?

   A. 0.8 leading power factor
   B. 0.8 lagging power factor
   C. zero power factor
   D. unity power factor

9. Negative voltage regulation is indicative that the load is___________?

   A. capacitive only
   B. inductive only
   C. inductive or resistive
   D. none of the above

10. Minimum voltage regulation occurs when the power factor of the load is_____________?

    A. unity
    B. lagging
    C. leading
    D. zero