A. decrease
B. become zero
C. remain the same
D. increase
Related Mcqs:
- 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 - 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 - 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 - 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 - 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 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 - 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 - 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 - The self-inductance of a solenoid is increased when a soft iron core is inserted into it. This is because the soft iron core_______________?
A. Decreases the resistance of the solenoid
B. Reduces the effect of eddy current
C. Improves the flux linkage between the turns of the coil
D. Increases the mutual inductance between the solenoid and the core - The emf induced in a coil by a changing magnetic flux may have unit as______________?
A. ms-1A
B. ms-2A-1
C. kgms2A-1
D. kgm2s-1A-1
