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ECE :: Materials and Components

  1. The resistance of a superconductor is

  2. A.
    low
    B.
    very low
    C.
    very very low
    D.
    zero

  3. Dielectric constant, under the condition of alternating fields, is a complex quantity.

  4. A.
    True
    B.
    False

  5. In an homogeneous dielectric subjected to an electric field E, the dipole moment per unit volume is ∈0(∈r - 1) E.

  6. A.
    True
    B.
    False

  7. For a superconductor, magnetisation M in a field H is

  8. A.
    extremely small
    B.
    - H
    C.
    - I
    D.
    zero

  9. The probability of recombination of electrons and holes in a semiconductor is proportional to

  10. A.
    density of electrons
    B.
    density of holes
    C.
    density of electrons and holes
    D.
    none of the above

  11. Assertion (A): The regular or irregular stacking of atoms has importanteffect on properties of materials.

    Reason (R): The arrangement of atoms in a given material can be studied using X-rays.

  12. 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

  13. If temperature is increased, the temperature coefficient of a metal

  14. A.
    increases
    B.
    decreases
    C.
    may increase or decrease
    D.
    remains constant

  15. The application of magnetic field to superconducting material

  16. A.
    increases transition temperature
    B.
    decreases transition temperature
    C.
    has no effect on transition temperature
    D.
    may increase or decrease the transition temperature

  17. Automobile ignition systems use the principle of

  18. A.
    resistance
    B.
    self inductance
    C.
    mutual inductance
    D.
    capacitance

  19. In a valence crystal, the valence electrons

  20. A.
    are not shared
    B.
    are shared between neighbouring atoms
    C.
    are shared by all atoms
    D.
    any of the above