In a primary coil 5 A current is flowing on 220 V. In the secondary coil 2200 V are produced. Ratio of number of turns in secondary coil and primary coil will be
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An oscillator circuit consists of an inductance of 0. mH and a capacitor of 20 μF. The resonant frequency of the circuit is nearly
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(a) 15.92 Hz (b) 159.2 Hz (c) 15.920Hz […]
The self induced e.m.f. in a 0.1 H coil when the current in it is changing at the rate of 200 amp/sec is
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(a) 8×10⁻⁴ V (b) 8×10⁻⁵ V (c) 20 V (d) […]
Two circuits have a mutual inductance of 0.1 H. What average e.m.f. is induced in one circuit when the current in the other circuit changes from 0 to 20 A in 0.02 s?
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A wire of length 1 m is moving at a speed of 2 ms⁻¹ perpendicular to its length in a homegeneous magnetic field of 0.5 T. If the ends of the wire are joined to […]
In circular coil, when number of turns is doubled and resistance becomes 1/4th of initial value, the inductance becomes
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(a) 8 times (b) 2 times (c) 4 times (d) No change
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If emf induced in a coil is 2 V by changing the current in it from 8 A to 6 A in 2×10⁻³ s, then the coefficient of self-induction is
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(a) 2×10⁻³ H […]
Two coils have the mutual inductance of 0.05 H. The current changes in the first coil as I=I₀ sin ωt, where I₀=1 A and ω=100π rad/s. The maximum emf induced in secondary coil is
An avarage induced e.m.f. of 1 V appears in a coil when the current in it is changed from 10 A in one direction to 10A in opposite direction in 0.5 sec. Self inductance of […]
When a magnet is taken towards a coil, the induced e.m.f. depends on
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(a) the number of turns in the coil (b) the speed of the magnet (c) the resistance of the coil […]
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