A transformer oil must be free from________________? - PakMcqs

Related Mcqs:

1. 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...

2. Gas is usually not liberated due to dissociation of transformer oil unless the oil temperature exceeds?

   A. 50°C B. 80°C C. 100°C D. 150°C...

3. 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...

4. The dielectric strength of transformer oil is expected to be______________?

   A. lkV B. 33 kV C. 100 kV D. 330 kV...

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

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

6. 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...

7. 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°...

8. Material used for construction of transformer core is usually___________________?

   A. wood B. copper C. aluminium D. silicon steel...

9. The noise produced by a transformer is termed as_______________________?

   A. zoom B. hum C. ringing D. buzz...

10. Which of the following statements regarding an idel single-phase transformer having a turn ratio of 1 : 2 and drawing a current of 10 A from 200 V A.C. supply is incorrect?

    A. Its secondary current is 5 A B. Its secondary voltage is 400 V C. Its rating is 2 kVA D. Its secondary current is 20 A E. It is a step-up transformer...