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  • Question
  • For crushing of solids, the Rittinger's law states that the work required for crushing is proportional to


  • Options
  • A. the new surface created.
  • B. the size reduction ratio.
  • C. the change in volume due to crushing.
  • D. none of these.

  • Correct Answer
  • the new surface created. 


  • Mechanical Operations problems


    Search Results


    • 1. The process by which fine solids is removed from liquids is termed as

    • Options
    • A. decantation
    • B. flocculation
    • C. sedimentation
    • D. classification
    • Discuss
    • 2. The critical speed of a trommel (N) is related to its dia (D) as

    • Options
    • A. N ?
    • B. N ? D
    • C. N ? D
    • D. N ?
    • Discuss
    • 3. __________ are mixed using ribbon blenders.

    • Options
    • A. Lumpy solids and low viscosity liquids
    • B. Dry powders
    • C. High viscosity liquids
    • D. Thick pastes
    • Discuss
    • 4. Work index is the gross energy (kWh/tonne of feed) necessary to reduce a very large feed to such a size that 80% of product particles will pass through a 0.1 mm screen. The value of work index determined for wet grinding should be multiplied with __________ to get the same for dry grinding.

    • Options
    • A. 1.0
    • B. 0.5
    • C. 1.34
    • D. 4.34
    • Discuss
    • 5. Shell and leaf filter as compared to plate and frame filter

    • Options
    • A. entails less labor cost.
    • B. facilitates filtration under higher pressure.
    • C. provides more effective washing.
    • D. all (a), (b) & (c)
    • Discuss
    • 6. Activators are those chemicals which help buoying up one mineral in preference to the other in the froth floatation process. Which of the following is an activator?

    • Options
    • A. Cresylic acid
    • B. Copper sulphate
    • C. Calcium carbonate
    • D. Sodium carbonate
    • Discuss
    • 7. Which of the following achieves the least reduction ratio for a given feed size?

    • Options
    • A. Jaw crusher
    • B. Roll crusher
    • C. Cone crusher
    • D. Gyratory crusher
    • Discuss
    • 8. As per Taggart's formula, the capacity (kg/hr) of Jaw & Gyratory crushers (for gapes of 10 to 60 cms) is equal to (where, L = Length of feed opening, cms S = Maximum width of discharge opening, cms )

    • Options
    • A. LS
    • B. 93 LS
    • C. 250 LS
    • D. LS
    • Discuss
    • 9. Which of the following crushing laws is most accurately applicable to the fine grinding of materials?

    • Options
    • A. Bond's crushing law
    • B. Kick's law
    • C. Rittinger's law
    • D. None of these.
    • Discuss
    • 10. For coarse reduction of hard solids, use

    • Options
    • A. impact
    • B. attrition
    • C. compression
    • D. cutting
    • Discuss


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