Home / ECE / Materials and Components :: Section 7

ECE :: Materials and Components

  1. A characteristic property of crystal is its periodicity of structure.

  2. A.
    True
    B.
    False

  3. If Bmax is the maximum flux density, hysteresis loss is proportional to

  4. A.
    Bmax
    B.
    B1.6max
    C.
    B2max
    D.
    B3max

  5. For making a capacitor it is better to have a dielectric having

  6. A.
    high permittivity
    B.
    low permittivity
    C.
    permittivity same as that of air
    D.
    permittivity which is neither high nor low

  7. In solid insulator materials having only one kind of atom, the types of polarization which exist are

  8. A.
    electronic only
    B.
    electronic and ionic
    C.
    electronic, ionic and permanent
    D.
    electronic and permanent

  9. Schrodinger wave equation is a

  10. A.
    linear equation
    B.
    differential equation
    C.
    partial differential equation
    D.
    none of the above

  11. Debye temperature of metals is

  12. A.
    about 10 K
    B.
    about 200 K
    C.
    about 600 K
    D.
    about 2 K

  13. If Bmax is the maximum flux density, eddy current loss is proportional to

  14. A.
    Bmax
    B.
    B1.6max
    C.
    B2max
    D.
    B3max

  15. As the viscosity of a liquid increases, the relaxation time

  16. A.
    remains constant
    B.
    increases
    C.
    decreases
    D.
    first decreases then increases

  17. A wire is carrying current I. The field intensity H at a distance r from the wire

  18. A.
    is directed towards wire
    B.
    is directed away from wire
    C.
    is tangential every where to a circle of radius r
    D.
    none of the above

  19. The materials which become polarized on the application of mechanical stress are called piezoelectric.

  20. A.
    True
    B.
    False