Q. Assertion (A): Ferroelectric materials have spontaneous polarization.
Reason (R): Above curie temperature, ∈ = C/(T-ϴ) for ferro-electric materials.

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Q. If e is the charge of an electron, R is the radius of its orbit and ω is the angular velocity of electron, the magnetic dipole moment μm of the orbit is |μm| = eωR².

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Q. If a piece of wood is placed in a magnetic field

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Q. The number of valence electrons in donor impurity are

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Q. In a true valence crystal, the bonding between the atoms is accomplished by the sharing of valence electrons.

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Q. Which of the following are donor impurities?

1. Gold
2. Phosphorus
3. Boron
4. Antimony
5. Arsenic
6. Induim

Select the correct answer using the following codes

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Q. If n denotes principal quantum number, the angular quantum number l = 0, 1... (n - 1).

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Q. Assertion (A): In a perfect capacitor, the current density is given by ω ∈₀E0∈'rcos(ωt + 90°), where ∈ᵣ' is real part of dielectric constant.
Reason (R): In a perfect capacitor, dielectric losses are zero.

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Q. Assertion (A): For a solenoid having N turns, B = µ₀µᵣNI/L .
Reason (R): For all magnetic materials, B increases linearly with I.

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Q. Assertion (A): If E is available energy state eV and EF is Fermi level, then probability of energy state E being occupied = 0.5.Reason (R): .

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Q. A parallel plate capacitor has its length, width and separation doubled. It fringing effects are neglected, to keep the capacitance same, the dielectric constant must be

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Q. Assertion (A): In imperfect capacitors, the current does not lead the applied ac voltage by 90°.
Reason (R): When subjected to ac fields, the dielectric constant can be expressed as ∈'r - j∈"r.

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Q. In atomic physics, a state with l = 0 is called p state.

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Q. If a sample of germanium and a sample of silicon have the same impurity density and are kept at room temperature

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Q. When an electric field E is applied to solid and liquid insulating materials, the internal field Ei acting at the location of atom is such that

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Q. Which element exhibits the property of inertia?

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Q. For a permanent magnetic material

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Q. In a coaxial cable, braided copper is used for

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Q. The hysteresis phenomenon in ferromagnetic materials exists at all temperatures.

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Q. Assertion (A): Magnetic susceptibility of diamagnetic materials is much less than that of paramagnetic materials.
Reason (R): For diamagnetic as well as paramagnetic materials, μᵣ is nearly equal to 1.

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