In a transformer the resistance between its primary and secondary should be_____________?

Related Mcqs:

1. If R2 is the resistance of secondary winding of the transformer and K is the transformation ratio then the equivalent secondary resistance referred to primary will be___________?

   A. R2/VK
   B. R2IK2
   C. R22!K2
   D. R22/K

2. In a transformer the resistance between its primary and secondary is____________?

   A. zero
   B. 1 ohm
   C. 1000 ohms
   D. infinite

3. An ideal transformer has infinite values of primary and secondary inductances. The statement is______________?

   A. true
   B. false

4. 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

5. 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

6. 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

7. 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

8. In a transformer the energy is conveyed from primary to secondary_________?

   A. through cooling coil
   B. through air
   C. by the flux
   D. none of the above

9. When a given transformer is run at its rated voltage but reduced frequency, its____________?

   A. flux density remains unaffected
   B. iron losses are reduced
   C. core flux density is reduced
   D. core flux density is increased

10. Auto-transformer makes effective saving on copper and copper losses, when its transformation ratio is_________________?

    A. approximately equal to one
    B. less than one
    C. great than one
    D. none of the above