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  • Question
  • The phenomenon of dielectric hysteresis occurs with


  • Options
  • A. dc
  • B. ac
  • C. both ac and dc
  • D. none of the above

  • Correct Answer
  • ac 

    Explanation
    Hysteresis phenomenon occurs when direction of electric field is changed. This can happen only with ac.

    Materials and Components problems


    Search Results


    • 1. The elements which become superconducting at extremely low temperatures are

    • Options
    • A. good conductors at room temperature
    • B. ferromagnetic at room temperature
    • C. relatively poor conductors at room temperature
    • D. insulators at room temperature
    • Discuss
    • 2. 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.

    • Options
    • A. 1 and 2 only
    • B. 2 and 3 only
    • C. 1 and 3 only
    • D. 1, 2 and 3
    • Discuss
    • 3. The residual resistivity of a binary alloy at 0 K is

    • Options
    • A. sum of residual resistivities of component metals
    • B. difference of residual resistivities of component metals
    • C. product of residual resistivities of component metals
    • D. dependent on the concentration of minor component in the alloy
    • Discuss
    • 4. If the number of atoms per unit volume of a monoatomic gas changes, the dielectric constant still remains constant.

    • Options
    • A. True
    • B. False
    • Discuss
    • 5. When a dielectric material is subjected to alternating field, the absorption of energy by the material from the field is given by the imaginary part of polarizability.

    • Options
    • A. True
    • B. False
    • Discuss
    • 6. Wood is a diamagnetic material.

    • Options
    • A. True
    • B. False
    • Discuss
    • 7. The magnetic quantum number determines the component of angular momentum along a prescribed direction.

    • Options
    • A. True
    • B. False
    • Discuss
    • 8. In an intrinsic semiconductor, at a given temperature T

    • Options
    • A. the number of electrons-hole pairs generated per second due to thermal motion are equal to the number of electron-hole pairs lost per second due to recombination
    • B. the number of electron-hole pairs generated per second due to thermal motion is always less than the number of electron-hole pairs lost per second due to recombination
    • C. the number of electron hole pairs generated per second due to thermal motion is always more than the number of electron-hole pairs lost per second due to recombination
    • D. any of the above
    • Discuss
    • 9. Curie Weiss law is .

    • Options
    • A. True
    • B. False
    • Discuss
    • 10. Electrical contact materials used in switches, brushes, relay must possess

    • Options
    • A. high thermal conductivity and high melting point
    • B. low thermal conductivity and low melting point
    • C. high thermal conductivity and low melting point
    • D. low thermal conductivity and high melting point
    • Discuss


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