The crushed material received for separation is called feed or_________________?

Related Mcqs:

1. 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________________?

   A. Easier grindability
   B. Poor grindability
   C. High power consumption in grinding
   D. None of these

2. 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.

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. 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

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

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

6. 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?

   A. 1.0
   B. 0.5
   C. 1.34
   D. 4.34

7. Which of the following equations is Rittinger’s crushing law? (Where P = power required by the machine, m = feed rate, k = a constant, D̅ sa & D̅ sb = volume surface mean diameter of feed & product respectively) ?

   A. P/m = K/ √Dp
   B. P/m = K . ln D̅ sa/D̅ sb
   C. P/m = K . (1/ D̅ sb – 1/D̅ sa)
   D. None of these

8. According to Bond crushing law, the work required to form particle of size ‘D’ from very large feed is (where (S/V)p and (S/V)f are surface to volume ratio of the product and feed respectively) ?

   A. (S/V)p
   B. √(S/V)p
   C. (S/V)2p
   D. (S/V)f

9. A sand mixture was screened through a standard 10-mesh screen. The mass fraction of the oversize material in feed, overflow and underflow were found to be 0.38, 0.79 and 0.22 respectively. The screen effectiveness based on the oversize is_________________?

   A. 0.50
   B. 0.58
   C. 0.68
   D. 0.62

10. Number of particles in a crushed solid sample is given by (where, m = mass of particles in a sample, Vp = volume of one particle, ρ= density of particles) ?

    A. m/ρ . Vp
    B. m . ρ/Vp
    C. m . Vp/ρ
    D. Vp/m . ρ