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ECE :: Materials and Components

  1. The magnetic quantum number determines the component of angular momentum along a prescribed direction.

  2. A.
    True
    B.
    False

  3. An electron is moving around a proton, in a circle of radius R. If flux density in the region is increased from zero to B, the force on the electron is

  4. A.
    B.
    eR (dB / dt)
    C.
    eRB
    D.

  5. Wood is a diamagnetic material.

  6. A.
    True
    B.
    False

  7. Curie Weiss law is .

  8. A.
    True
    B.
    False

  9. Consider the following materials

    1. Nickel
    2. Silver
    3. Oxygen
    4. Aluminium
    The correct sequence in the order of decreasing permeability is

  10. A.
    1, 4, 3, 2
    B.
    1, 4, 2, 3
    C.
    4, 1, 3, 2
    D.
    4, 1, 2, 3

  11. The unit for mmf is

  12. A.
    A
    B.
    Wb
    C.
    T
    D.
    V

  13. A magnetic field exists around

  14. A.
    moving charges
    B.
    static charges
    C.
    iron
    D.
    copper

  15. A conductor carries 10 A current in + x direction and is lying in a field having a flux density 0.2 T directed along + z direction. The magnitude of force per metre length and direction are

  16. A.
    2 N, + y direction
    B.
    2 N, - y direction
    C.
    0.02 N, + y direction
    D.
    0.02 N, - y direction

  17. The residual resistivity of a binary alloy at 0 K is

  18. 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

  19. The resistance of a photoconductor

  20. A.
    increases with increase in light intensity
    B.
    decreases with increase in light intensity
    C.
    may increase or decrease with increase in light intensity
    D.
    remains constant