Both the number of turns and the core length of an inductive coil are doubled. Its self-inductance will be_____________?

Related Mcqs:

1. The core of a coil has a length of 200 mm. The inductance of coil is 6 mH. If the core length is doubled, all other quantities, remaining the same, the inductance will be_____________?

   A. 3 mH
   B. 12 mH
   C. 24mH
   D. 48mH

2. A 200 turn coil has an inductance of 12 mH. If the number of turns is increased to 400 turns, all other quantities (area, length etc.) remaining the same, the inductance will be___________?

   A. 6 mH
   B. 14 mH
   C. 24 mH
   D. 48 mH

3. In an iron cored coil the iron core is removed so that the coil becomes an air cored coil. The inductance of the coil will_____________?

   A. increase
   B. decrease
   C. remain the same
   D. initially increase and then decrease

4. Two coils have self-inductances of 10 H and 2 H, the mutual inductance being zero. If the two coils are connected in series, the total inductance will be_____________?

   A. 6 H
   B. 8 H
   C. 12 H
   D. 24 H

5. The self-inductance of the coil may be defined as equal to the e.m.f. induced in volts when the current in the circuit changes at the rate of unit Weber turns

   A. Yes
   B. No

6. A coil is wound on iron core which carries current I. The self-induced voltage in the coil is not affected by________________?

   A. variation in coil current
   B. variation in voltage to the coil
   C. change of number of turns of coil
   D. the resistance of magnetic path

7. If the secondary coil has Ns turns and the primary Np turns the relation between secondary and primary voltages is given by_____________?

   A. Vs/Vp = Np/Ns
   B. Vs/Vp = Ns/Np
   C. Vp/Vs = Ns/Np
   D. Vp/Vs = Np/Ns

8. A coil of wire is arranged with its plane perpendicular to a uniform magnetic field o flux density B. when the radius of the coil increases from r1 to r2 in time Δt then what is the emf induced in the coil ?

   A. ωB/r22-r12/Δt
   B. ωB(r2-r1)2/Δt
   C. ωB(r22-r12)/Δt
   D. ωB(r22+r12)/Δt

9. A small coil lies inside a large coil. The two coils are horizontal concentric and carry currents in opposite directions. The large coil will experience______________?

   A. A torque about horizontal axis
   B. A torque about vertical axis
   C. An upward force along the axis
   D. No resultant force

10. Self inductance of a coil depends upon________________?

    A. current flowing
    B. number of turns per unit length
    C. voltage produce
    D. all