Q. For magnetic shielding, we need a ferromagnetic material.

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Q. Assertion (A): Electronic polarizability increases as atoms becomes larger.

Reason (R): For rare gas, ∈₀(∈ᵣ - 1) E = Nαe, where N is number of atoms/m³ and αe is electronic polarizability of material.

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Q. In a metal, the valence electrons

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Q. All magnetic materials exhibit the phenomenon of saturation.

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Q. On the basis of the type of chemical bonds, solids may be classified into

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Q. The units for intrinsic strength of dielectric are

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Q. Specific resistance of silver is about

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Q. The v-i relation for an arc is v = 44 + 30/i . If v = 50 V, i =

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Q. Assertion (A): If an electron having charge e is revolving in an orbit of radius R and with angular velocity ω, the magnetic dipole moment of orbit is 0.5 eωR².

Reason (R): Orbital angular momentum and magnetic dipole moment are always equal.

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Q. Assertion (A): A capacitor with imperfect dielectric can be represented by a capacitance in parallel with resistance.

Reason (R): For imperfect dielectrics, dielectric constant has real and imaginary parts.

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Q. An atom of a rare gas is placed is an electric field E. Then

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Q. In van der walls crystals, there exists a high degree of stability of the outer electron shell.

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Q. As per temperature limits, the number of categories of solid dielectrics are

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Q. At room temperature the number of conducting electrons in an intrinsic semiconductor

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Q. Assertion (A): The angular momentum of an atom is due to three contributions viz. orbital, electron spin and nuclear spin.

Reason (R): The nuclear spin magnetic moment is much more than electron spin magnetic moment.

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Q. If WF is the Fermi level, then in a metal at T = 0

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Q. Silicon and germanium have diamond structure. The number of atoms in a volume equal to a³ where a is the edge of elementary cube are

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Q. If the radius of electron cloud around the nucleus of a rare gas atom is R, the electronic polarizability of the atom is porportional to

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Q. By inserting a plate of dielectric between the plates of a parallel plate capacitor, the energy stored in the capacitor is increased five times. The dielectric constant of material is

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Q. Debye temperature of metals is

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