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______________?

Related Mcqs:

1. 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

2. 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

3. A series resonant band-stop filter consists of a 68 Ω resistor, a 110 mH coil, and a 0.02 µF capacitor. The internal resistance, RW, of the coil is 4 Ω. Input voltage is 200 mV. Output voltage is taken across the coil and capacitor in series. What is the output voltage magnitude at f0?

   A. 1.1 mV
   B. 11.1 mV
   C. 111 mV
   D. 200 mV

4. A parallel resonant band-pass filter consists of a 90 Ω resistor in series with a parallel network made up of a 60 mH coil and a 0.02 µF capacitor. The output is taken across the capacitor/coil. The coil winding has a resistance of 20 Ω. What is the center frequency of the filter?

   A. 459 Hz
   B. 4,591 Hz
   C. 999 Hz
   D. 2,176 Hz

5. Two coils have inductances of 8 mH and 18 mH and a co-efficient of coupling of 0.5. If the two coils are connected in series aiding, the total inductance will be______________?

   A. 32 mH
   B. 38 mH
   C. 40 mH
   D. 48 mH

6. The self inductances of two coils are 8 mH and 18 mH. If the co-efficients of coupling is 0.5, the mutual inductance of the coils is______________?

   A. 4 mH
   B. 5 mH
   C. 6 mH
   D. 12 mH

7. 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

8. 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__________?

   A. self-inductance
   B. mutual inductance
   C. series aiding inductance
   D. capacitance

9. 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

10. In case all the flux from the current in coil 1 links with coil 2, the co-efficient of coupling will be____________?

    A. 2.0
    B. 1.0
    C. 0.5
    D. zero