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Chemical Engineering :: Chemical Engineering Basics

  1. Heat treatment of steel is done to mainly change its __________ properties.

  2. A.
    physical
    B.
    chemical
    C.
    mechanical
    D.
    surface

  3. Normal dosage of chlorine in public water supply scheme ranges from __________ ppm.

  4. A.
    0.5 to 1
    B.
    10 to 15
    C.
    300 to 500
    D.
    1000 to 1500

  5. Cast iron has the unique property of high

  6. A.
    ductility
    B.
    damping characteristics
    C.
    hardness
    D.
    malleability

  7. Thermal shock produced by cooling is more dengerous/deleterious than that produced by heating a surface, because of the reason that

  8. A.
    cooling produces tension on the surface.
    B.
    cooling produces compression on the surface.
    C.
    heating does not produces any thermal stress.
    D.
    heating produces compression on the surface.

  9. The hardness of a grinding wheel is specified by the

  10. A.
    alphabetical letter.
    B.
    Rockwell hardness number.
    C.
    Brinell hardness number.
    D.
    none of these.

  11. Scaling occurs in boiler tubes due to the fact that, the solubility of Ca(OH)2 __________ with increasing temperature.

  12. A.
    increases
    B.
    decreases
    C.
    shows inversion of solubility
    D.
    none of these

  13. While the recrystallisation temperature for pure metals is 0.3 Tm, the same for alloys is equal to __________ x Tm (where, Tm Melting temperature).

  14. A.
    0.25
    B.
    0.45
    C.
    0.70
    D.
    0.95

  15. The factor of safety for brittle materials (having elongation < 5%) is based on the __________ stress.

  16. A.
    yield
    B.
    proof
    C.
    ultimate
    D.
    none of these

  17. Carburettor in a spark ignition engine is used to

  18. A.
    mix air-fuel in the desired ratio.
    B.
    maintain a constant speed at varying loads.
    C.
    adjust the stroke length.
    D.
    increase the compression ratio.

  19. __________ are not emitted by radioactive substances.

  20. A.
    α-rays
    B.
    β-rays
    C.
    protons
    D.
    positrons