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  • Question
  • The energy required per unit mass to grind limestone particles of very large size to 100 ?m is 12.7 kWh/ton. An estimate (using Bond's law) of the energy to grind the particles from a very large size to 50 ?rn is


  • Options
  • A. 6.35 kWh/ton
  • B. 9.0 kWh/ton
  • C. 18 kWh/ton
  • D. 25.4 kWh/ton

  • Correct Answer
  • 18 kWh/ton 


  • Mechanical Operations problems


    Search Results


    • 1. Highly viscous liquids & pastes are agitated by

    • Options
    • A. propellers
    • B. turbine agitators
    • C. multiple blade paddles
    • D. none of these
    • Discuss
    • 2. Diatomaceous earth is a/an

    • Options
    • A. explosive
    • B. filter aid
    • C. filter medium
    • D. catalyst
    • Discuss
    • 3. Filter aids like asbestos, kieselguhr, diatomaceous earth etc. are used to increase the porosity of the final filter cake & reducing the cake resistance during filtration. Filter aid is

    • Options
    • A. added to the feed slurry.
    • B. precoated on the filter medium prior to filtration.
    • C. separated from the cake by dissolving solids or by burning it off.
    • D. all 'a', 'b'&'c'.
    • Discuss
    • 4. Which of the following is the most suitable for handling fibrous and dense slurries?

    • Options
    • A. Propeller agitator
    • B. Cone type agitator
    • C. Turbine agitator
    • D. Radial propeller agitator
    • Discuss
    • 5. The capacity of a pneumatic conveying system depends upon the

    • Options
    • A. bulk density of materials.
    • B. pressure of the conveying air.
    • C. diameter of the conveying line.
    • D. all (a), (b) and (c).
    • Discuss
    • 6. Jigging is a technique by which different particles can be

    • Options
    • A. separated by particle size.
    • B. separated by particle density.
    • C. separated by particle shape.
    • D. mixed.
    • Discuss
    • 7. Tabular bowl centrifuges as compared to disk bowl centrifuges

    • Options
    • A. operate at higher speed.
    • B. employ bowl of larger diameter.
    • C. can not be operated under pressure/vacuum.
    • D. can't be used for separation of fine suspended solids from a liquid.
    • Discuss
    • 8. Power required to drive a ball mill with a particular ball load is proportional to (where, D = diameter of ball mill )

    • Options
    • A. D
    • B. 1/D
    • C. D2.5
    • D. 1/D2.5
    • Discuss
    • 9. Diesel index.(an alternative index for expressing the quality of diesel) is

    • Options
    • A. determined by using a test engine.
    • B. not related to aniline point.
    • C. equal to cetane number plus 3.
    • D. all (a), (b) & (c).
    • Discuss
    • 10. __________ determination is not a very significant and important test for gasoline.

    • Options
    • A. Gum & sulphur content
    • B. Viscosity
    • C. Octane number
    • D. Reid vapor pressure
    • Discuss


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