Q. Assertion (A): Diamond and carborudum are both very hard materials.

Reason (R): Valence band can be extremely strong.

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Q. The chemical properties of atoms are determined by all the electrons and their configuration.

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Q. Nichrome is used for

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Q. If k is Boltzmann's constant and T is absolute temp, then at room temp.

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Q. If the valence electron is separated from a copper atom, the remaining part of atom has a net charge of

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Q. The number of tightly bound electrons in silicon atom are

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Q. Electric dipole moment is usually expressed in debye units. Here, 1 debye unit equals

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Q. A particle of charge Q coulombs is bound elastically to an equilibrium position with a force constant of f newton per metre. The polarizability of the system is

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Q. 1 Bohr magneton = eh/(4πm) .

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Q. An electron (charge -e) is rotating in a circular orbit of radius R, around a proton with charge +e at a constant angular velocity ω. The orbital magnetic dipole moment is

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Q. The dielectrics having only one kind of atoms are known as elemental dielectrics.

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Q. For a core having a relative permeability μᵣ, magnetic dipole moment per unit volume M and field strength H, the flux density B is

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Q. The law that K/σT (where K is thermal conductivity, σ is electrical conductivity and T is absolute temperature) for all metals is equal to a universal constant is known as

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Q. In elemental dielectrics, the orientation and ionic polarization are absent.

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Q. In which of the following semiconductor are holes majority carriers

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Q. The equation D = ∈₀∈ᵣ E refers only to isotropic materials.

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Q. When a ferromagnetic substance is magnetised there are small changes in dimensions. This phenomenon is called

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Q. Assertion (A): In some materials, Ɛᵣ is independent of temperature while in others, Ɛᵣ depends on temperature.

Reason (R): If permanent dipoles are absent, Ɛᵣ varies with temperature.

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Q. An electron in a homogeneous magnetic field and having velocity perpendicular to the direction of field moves

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Q. Spontaneous polarization occurs in ferroelectric materials.

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