A. 0.5
B. 2
C. 5
D. 10
Related Mcqs:
- In a size reduction crushing operation, feed size is 300 to 1500 mm while the product size is 100 to 300 mm. This is a case of the ________________ crushing?
A. Secondary
B. Fine
C. Primary
D. Ultrafine - In a size reduction crushing operation, feed size is 100 to 300 mm. while the product size is 10 to 50 mm. This is a case of the _____________ crushing?
A. Primary
B. Secondary
C. Fine
D. Ultrafine - In a size reduction crushing operation, the feed size is 10 to 50 mm, while the product size is 2 to 10 mm. This is a case of _______________ crushing?
A. Primary
B. Secondary
C. Fine
D. Ultrafine - 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 - 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 - Which of the following terminology is not used for size reduction of materials to fine sizes or powders ?
A. Comminution
B. Dispersion
C. Pulverisation
D. Compression - General crushing equation is given by d(P/m) = -K (dD̅ S/D̅ n S). Bond’s crushing law is obtained by solving this equation for n = _____________ and feed of infinite size?
A. 1
B. 1.5
C. 2
D. 2.5 - 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 - What is the usual value of angle of nip for crushing of ordinary rock in smooth steel crushing rolls?
A. 16°
B. 32°
C. 40°
D. 46° - 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
