Helical coils can be used on___________?

Related Mcqs:

1. Helical coils can be used on___________________?

   A. low voltage side of high kVA transformers
   B. high frequency transformers
   C. high voltage side of small capacity transformers
   D. high voltage side of high kVA rating transformers

2. Spacers are provided between adjacent coils?

   A. to provide free passage to the cooling oil
   B. to insulate the coils from each other
   C. both A. and (b)
   D. none of the above

3. A transformer core is laminated to__________?

   A. reduce hysteresis loss
   B. reduce eddy current losses
   C. reduce copper losses
   D. reduce all above losses

4. 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

5. Transformer breaths in when_______________?

   A. load on it increases
   B. load on it decreases
   C. load remains constant
   D. none of the above

6. 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

7. Delta/star transformer works satisfactorily when______________?

   A. load is balanced only
   B. load is unbalanced only
   C. on balanced as well as unbalanced loads
   D. none of the above

8. Which of the following loss in a transformer is zero even at full load ____________?

   A. Core loss
   B. Friction loss
   C. Eddy current loss
   D. Hysteresis loss

9. Short circuit test on transformers is conducted to determine____________?

   A. hysteresis losses
   B. copper losses
   C. core losses
   D. eddy current losses

10. Which of the following insulating materials can withstand the highest temperature safely ?

    A. Cellulose
    B. Asbestos
    C. Mica
    D. Glass fibre