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  • Question
  • Assertion (A): For a dielectric, P = ?0(?r - 1) E.

    Reason (R): Dipole moment per unit volume is called polarization of dielectric.


  • Options
  • A. Both A and R are true and R is correct explanation of A
  • B. Both A and R are true but R is not correct explanation of A
  • C. A is true but R is false
  • D. A is false but R is true

  • Correct Answer
  • Both A and R are true but R is not correct explanation of A 

    Explanation
    The two statements are correct but independent of each other.

    Materials and Components problems


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    • 1. If v is velocity of electron, ?0 is absolute permittivity, m is mass of electron, e is charge on electron and r is the radius of orbit of electron in hydrogen atom, the stability of orbit requires the following equation to be satisfied

    • Options
    • A.
    • B.
    • C.
    • D.
    • Discuss
    • 2. Assertion (A): Ferrites are very useful at very high frequencies.

      Reason (R): Ferrites have high permeability and high resistivity.


    • Options
    • A. Both A and R are true and R is correct explanation of A
    • B. Both A and R are true but R is not correct explanation of A
    • C. A is true but R is false
    • D. A is false but R is true
    • Discuss
    • 3. Macroscopic quantities of a given material

    • Options
    • A. are absolutely constant
    • B. are a function of temperature
    • C. are a function of temperature, pressure field
    • D. none of the above
    • Discuss
    • 4. For an insulating material, dielectric strength and dielectric losses should be

    • Options
    • A. high and high
    • B. low and high
    • C. high and low
    • D. low and low
    • Discuss
    • 5. As the temperature of semiconductor is increased

    • Options
    • A. the average number of free charge carriers decreases
    • B. the average number of free charge carriers increases
    • C. the average number of free charge carriers remains the same
    • D. the average number of free charge carriers may increase or decrease
    • Discuss
    • 6. Eddy current loss is

    • Options
    • A. proportional to frequency
    • B. independent of frequency
    • C. proportional to (frequency)2
    • D. proportional to (frequency)3
    • Discuss
    • 7. Consider the following statement: In case of a superconductor

      1. B = 0
      2. ?r is high
      3. diamagnetism is high
      4. transition temperature varies with isotopic mass.
      Of the above statements

    • Options
    • A. 1 and 2 are correct
    • B. 2, 3, 4 are correct
    • C. 1, 3, 4 are correct
    • D. 2, 4 are correct
    • Discuss
    • 8. Assertion (A): In liquids and glassy substances, dielectric losses occur.

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


    • Options
    • A. Both A and R are true and R is correct explanation of A
    • B. Both A and R are true but R is not correct explanation of A
    • C. A is true but R is false
    • D. A is false but R is true
    • Discuss
    • 9. The dipole moment per unit volume P as a function of E for an insulator is

    • Options
    • A. P = ?0 E(?r)
    • B. P = ?0 E
    • C. P = ?0(?r - 1) E
    • D. P =
    • Discuss
    • 10. The current flow in a semiconductor is due to

    • Options
    • A. holes
    • B. electrons
    • C. holes and electrons
    • D. holes, electrons and ions
    • Discuss


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