The hum in a transformer is mainly attributed to______________?

Related Mcqs:

1. Which of the following is the main advantage of an auto-transformer over a two winding transformer?

   A. Hysteresis losses are reduced B. Saving in winding material C. Copper losses are negligible D. Eddy losses are totally eliminated...

2. The changes in volume of transformer cooling oil due to variation of atmospheric temperature during day and night is taken care of by which part of transformer?

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

3. 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...

4. Which winding in a transformer has more number of turns ?

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

5. Hysteresis loss in a transformer varies as CBmax = maximum flux density) ?

   A. Bmax B. Bmax1-6 C. Bmax1-83 D. B max...

6. Harmonics in transformer result in___________?

   A. increased core losses B. increased I2R losses C. magnetic interference with communication circuits D. all of the above...

7. If a transformer is continuously operated the maximum temperature rise will occur in_______________?

   A. core B. windings C. tank D. any of the above...

8. A Transformer transforms____________?

   A. voltage B. current C. current and voltage D. power...

9. The transformer oil should have _______ volatility and _______ viscosity?

   A. low,low B. high,high C. low,high D. high,low...

10. The secondary of a current transformer is always short-circuited under operating conditions because it____________________?

    A. avoids core saturation and high voltage induction B. is safe to human beings C. protects the primary circuit D. none of the above...