ECE :: Materials and Components
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A good dielectric should have
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Magnetic hysteresis phenomenon is explained by
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If a metal specimen has n valence electrons per m3 each having charge e and mass m and t is the relaxations time, the conductivity is
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The relation between thermal conductivity K (W/m/°C), heat flow density Q (watt/m2) and dT/dx (°C per metre) is
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As per Matthiessen's rule, the total resistivity r of a conductor can be written as r = ri + aT, where ri and a are constants and T is absolute temperature. At very low temperatures
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Consider the following statement: In case of a superconductor
- B = 0
- μr is high
- diamagnetism is high
- transition temperature varies with isotopic mass.
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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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A single layer air cored coil has n turns and inductance L. If a new coil is formed by having 2n turns while keeping the coil length and diameter the same, the new inductance is
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The colour code on a carbon resistor is yellow-violet-orange. The value of resistance is
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A dielectric of relative permittivity ∈r is subjected to a homogeneous electric field E. The dipole moment P per unit volume is given by
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