# Home / ECE / Electromagnetic Induction :: section-1

### ECE :: Electromagnetic Induction

1. The property of coil by which a counter e.m.f. is induced in it when the current through the coil changes is known as

2.  A.  Self-inductance B.  Mutual inductance C.  Series aiding inductance D.  Capacitance   3. Which circuit element(s) will oppose the change in circuit current?

4.  A.  Resistance only B.  Inductance only C.  Capacitance only D.  Inductance and capacitance   5. Which of the following circuit elements will oppose the change in circuit current?

6.  A.  Capacitance B.  Inductance C.  Resistance D.  All of the above   7. In case all the flux from the current in coil 1 links with coil 2, the coefficient of coupling will be

8.  A.  2.0 B.  1.0 C.  0.5 D.  Zero   9. Two 300 uH coils in series without mutual coupling have a total inductance of

10.  A.  300 uH B.  600 uH C.  150 uH D.  75 uH   11. Which of the following is not a unit of inductance?

12.  A.  Henry B.  Coulomb/volt ampere C.  Volt second per ampere D.  All of the above   13. Which of the following is unit of inductance?

14.  A.  Ohm B.  Henry C.  Ampere turns D.  Weber/metre   15. An open coil has

16.  A.  Zero resistance and inductance B.  Infinite resistance and zero inductance C.  Infinite resistance and normal inductance D.  Zero resistance and high inductance   17. The self inductances of two coils are 8 mH and 18 mH. If the coefficient of coupling is 0.5, the mutual inductance of the coils is

18.  A.  4 mH B.  5 mH C.  6 mH D.  12 mH   19. Reversing the field or the current will reverse the force on the conductor.

20.  A.  Yes B.  No   