Q. If the diameter of a wire is doubled, its current carrying capacity becomes

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Q. The law J = σE, where J is current density, σ is electrical conductivity and E is field strength is

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Q. Assertion (A): Silicon is less sensitive to changes in temperature than germanium.
Reason (R): Cut in voltage in silicon is less than that in germanium.

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Q. Material which lack permanent magnetic dipoles are known as

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Q. The attraction between the nucleus and valence electron of copper atom is

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Q. If the temperature of an extrinsic semiconductor is increased so that the intrinsic carrier concentration is doubled, then

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Q. There is no hysteresis phenomenon is any dielectric material.

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Q. The units of μ₀ and μᵣ are

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Q. In metals the valence electron wave functions are strongly perturbed by the presence of neighbouring atoms.

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Q. The classes of solid dielectrics are

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Q. A 200 turn coil has a self inductance of 10 mH. If the number of turns is doubled, all other quantities remaining the same, the self inductance will be

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Q. A material which is lightly repelled by a magnetic field is known as

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Q. Which of the following is the poorest conductor of electricity?

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Q. The magnetic moment in units of Bohr magneton of a ferrous ion in any ferrite is

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Q. Assertion (A): The optical dielectric constant (i.e., εr at optical frequencies)of ionic dielectrics is less than static dielectric constant.

Reason (R): At optical frequencies, Pi = 0.

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Q. A piece of iron is placed in a magnetic field

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Q. Assertion (A): Magnetism can be explained by the theory of magnetic domains.

Reason (R): The existence of magnetic domains is evident from the Bitter powder patterns.

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Q. Ferromagnetic materials

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Q. In a specimen of ferromagnetic material, as the flux density is increased from zero to 2.5 T, µᵣ will

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Q. In molecules of ionic crystals, orientation polarization is zero.

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