Material used for construction of transformer core is usually___________________?

Related Mcqs:

1. Which of the following property is not necessarily desirable in the material for transformer core ?

   A. Mechanical strength
   B. Low hysteresis loss
   C. High thermal conductivity
   D. High permeability

2. Which of the following properties is not necessarily desirable for the material for transformer core ?

   A. Low hysteresis loss
   B. High permeability
   C. High thermal conductivity
   D. Adequate mechanical strength

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. 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

5. The purpose of providing iron core in a step-up transformer is?

   A. to provide coupling between primary and secondary
   B. to increase the magnitude of mutual flux
   C. to decrease the magnitude of mag-netizing current
   D. to provide all above features

6. The core used in high frequency transformer is usually___________?

   A. copper core
   B. cost iron core
   C. air core
   D. mild steel core

7. When secondary of a current transformer is open-circuited its iron core will be__________?

   A. hot because of heavy iron losses taking place in it due to high flux density
   B. hot because primary will carry heavy current
   C. cool as there is no secondary current
   D. none of above will happen

8. The size of a transformer core will depend on__________?

   A. frequency
   B. area of the core
   C. flux density of the core material
   D. A. and B. both

9. Reduction in core losses and increase in permeability are obtained with transformer employing__________?

   A. core built-up of laminations of cold rolled grain oriented steel
   B. core built-up of laminations of hot rolled sheet
   C. either of the above
   D. none of the above

10. 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