Kick’s law assumes that the energy required for size reduction is proportional to the logarithm of the ratio between the initial and the final diameters. The unit of Kick’s constant is_________________?

Related Mcqs:

1. The reduction ratio for grinders is defined as (where, Df and Dp are average diameters of feed and product respectively) ?

   A. Df/Dp
   B. Dp/Df
   C. Df – Dp
   D. None of these

2. 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

3. For crushing of solids, the Rittinger’s law states that the work required for crushing is proportional to __________________?

   A. The new surface created
   B. The size reduction ratio
   C. The change in volume due to crushing
   D. None of these

4. 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

5. 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

6. The constants (Kb, Kr and Kk) used in the laws of crushing (i.e., Bond’s law, Rittinger’s law and Kick’s law) depend upon the_________________?

   A. Feed material
   B. Type of crushing machine
   C. Both A. & B.
   D. Neither A. nor B.

7. Which of the following gives the work required for size reduction of coal to -200 mesh in a ball mill most accurately?

   A. Rittinger’s law
   B. Kick’s law
   C. Bond’s law
   D. None of these

8. Horsepower required for a roll crusher is directly proportional to its__________________?

   A. Reduction ratio
   B. Capacity
   C. Both A. & B.
   D. Neither A. nor B.

9. Power required to drive a ball mill with a particular ball load is proportional to (where, D = diameter of ball mill.) ?

   A. D
   B. 1/D
   C. D2.5
   D. 1/D2.5

10. The power number for a stirred tank becomes constant at high Reynolds number. In this limit, the variation of power input with impeller rotational speed (N) is proportional to___________________?

    A. N°
    B. N1
    C. N2
    D. N3