Energy in a current carrying coil is stored in the form of
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(a) electrical energy (b) magnetic field (c) heat (d) None of these
Correct Answer:
magnetic field
Explanation:
In a current carrying […]
In an LCR circuit, capacitance is changed from C to 2C. For the resonant frequency to remain unchanged, the inductance should be changed from L to
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(a) 4 L (b) 2 L (c) […]
The material suitable for making electromagnets should have
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(a) High retentivity and high coercivity (b) Low retentivity and low coercivity (c) high retentivity and low coercivity (d) Low retentivity and high coercivity
Radiofrequency choke uses core of
Options
(a) Air (b) Iron (c) Air and iron (d) None of these
Correct Answer:
Air
Explanation:
Radio frequencies are higher frequencies. Air core chokes are therefore used.
The magnetic flux linked with a circuit of resistance 100Ω increases from 10 to 60 Wb. The amount of induced charge that flows in the circuit is (in coulomb)
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(a) 0.5 (b) 5 […]
The coefficient of mutual inductance of two coils is 6 mH. If the current flowing in one is 2A, the induced e.m.f. in the second coil will be
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(a) Zero (b) 3 V […]
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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