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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Q. Lines of magnetic field cannot intersect.

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Q. At T = 0, the resistivity of a perfect single crystal of a metal is

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Q. In a polyatomic gas, the types of polarization which exist together are

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Q. Assertion (A): Metals are better heat conductors than insulators.

Reason (R): If dT/dx is temperature gradient, Q is heat flow density and K is thermal conductivity, then Q = - K (dT/dx).

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Q. In a virgin specimen of iron, the direction of spontaneous magnetisation varies from domain to domain.

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Q. Which of the following is used in lightning arresters?

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Q. High frequency inductors and capacitors are commonly plated with silver. The main purpose of this is to

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Q. In its lowest state, the electron is bound to the field of proton by an energy equal to

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Q. In a ferromagnetic material, the internal field seen by a dipole is

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Q. Consider the following statement: In case of a superconductor

1. B = 0
2. μᵣ is high
3. diamagnetism is high
4. transition temperature varies with isotopic mass.

Of the above statements

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Q. Assertion (A): In liquids and glassy substances, dielectric losses occur.

Reason (R): The orientation polarization in many substances is frequency dependent.

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