A. 6 mH
B. 14 mH
C. 24 mH
D. 48 mH
Related Mcqs:
- 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 - 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 - Both the number of turns and the core length of an inductive coil are doubled. Its self-inductance will be_____________?
A. unaffected
B. doubled
C. halved
D. quadrupled - 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 - 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 - 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 - 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 - 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 - An e.m.f. of 16 volts is induced in a coil of inductance 4H. The rate of change of current must be______________?
A. 64 A/s
B. 32 A/s
C. 16 A/s
D. 4 A/s - A coil induces 350 mV when the current changes at the rate of 1 A/s. The value of inductance is___________?
A. 3500 mH
B. 350 mH
C. 250 mH
D. 150 mH
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