Rittinger’s number designates the new surface created per unit mechanical energy absorbed by the material being crushed. Larger value of Rittinger’s number of a material indicates its________________?

Related Mcqs:

1. Rittinger number which designates the new surface produced per unit of mechanical energy absorbed by the material being crushed, depends on the ______________________?

   A. State or manner of application of the crushing force
   B. Ultimate strength of the material
   C. Elastic constant of the material
   D. All A., B. and C.

2. Energy requirement (per unit mass of material crushed/ground) is highest for__________________?

   A. Jaw crusher
   B. Rod mill
   C. Ball mill
   D. Fluid energy mill

3. Theoretical capacity of crushing rolls in tons/hr is given by (where, V = peripheral velocity, m/sec. W = width of rolls, m Dr = distance between rolls ρ = density of material to be crushed, kg/m3 here, V =πND where, N = speed of the rolls in rotation per second (rps) D = diameter of rolls, m) ?

   A. 3.6 V.W.Dr.ρ
   B. 3.6 V.W. ρ
   C. 3.6 W.Dr.ρ
   D. 3.6 V.W.Dr/ρ

4. The crushed material received for separation is called feed or_________________?

   A. Tailing
   B. Heading
   C. Concentrate
   D. Middling

5. The material is crushed in a gyratory crusher by the action of__________________?

   A. Impact
   B. Compression
   C. Attrition
   D. Cutting

6. The energy required per unit mass to grind limestone particles of very large size to 100 μm 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 μm is________________?

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

7. Mechanical conveyors which push the material along an endless trough or tube are called scrappers. Which of the following conveying equipments comes under the category of „scrappers‟ ?

   A. Bucket conveyor
   B. Flight conveyor
   C. Screw conveyor
   D. Both B. and C.

8. Specific surface area is the surface area of a unit _______________ of materials?

   A. Weight
   B. Volume
   C. Either A. or B.
   D. Neither A. nor B.

9. Sphericity is the ratio of the surface area of a spherical particle having the same volume as the particle to the surface area of the particle. Which of the following has the maximum value of sphericity ?

   A. Sphere
   B. Cube
   C. Cylinder (L/D = 1)
   D. Raschig rings

10. The optimum moisture content in solids to be crushed/ground ranges from _______________ percent?

    A. 3 to 4
    B. 8 to 10
    C. 10 to 15
    D. 15 to 20