Q. Assertion (A): If an atom of polarizability a is placed in homogeneous field E, the energy stored is 0.5 αE².

Reason (R): Capacitance of an isolated conducting sphere R in vacuum is 4 π∈₀ R farads.

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Q. Which of the following are true for relative dielectric constant?

1. It is dimensionless.
2. It is equal to 1 for vacuum.
3.It is equal to 1 for all substances.

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Q. Schrodinger wave equation is partial differential equation.

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Q. Hall effect is observed in a specimen (metal or semi- conductor) when it is carrying current and is placed in a magnetic field. The resultant electric field inside the specimen is

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Q. The capacitance of a capacitor is not affected by

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Q. The unit for mmf is

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Q. A magnetic field exists around

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Q. A conductor carries 10 A current in + x direction and is lying in a field having a flux density 0.2 T directed along + z direction. The magnitude of force per metre length and direction are

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Q. The residual resistivity of a binary alloy at 0 K is

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Q. The resistance of a photoconductor

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Q. Assertion (A): Electron concentration n, hole concentration p and charge concentration ni are related by ni² = np.

Reason (R): p type semiconductor is obtained by adding trivalent impurity to intrinsic semiconductor.

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Q. The temperature at which some materials become superconductors is called

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Q. In Fermi-Dirac statistics, the probability of electron occupation of an energy level equal to Fermi level is

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Q. The quantum numbers associated with electron motion are designed as

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Q. The carrier mobility in a semiconductor is 0.4 m²/Vs. Its diffusion constant at 300 K will be (in m²/s)

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Q. Which of these has lowest dielectric strength?

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Q. The maximum temperature limit of class B insulation is

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Q. Resistivity of metals consists of two parts, one part constant and the other temperature dependent.

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Q. The number of valence electrons in germanium atom is

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Q. Assertion (A): ∈₀ has the dimensions of farad per meter.

Reason (R): D = ∈₀∈ᵣ E.

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