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