This set of Mechanical Operations Multiple Choice Questions & Answers (MCQs) focuses on “Size Reduction”.
1. According to Rittingers law, work required is proportional to _________
a) Energy Consumed
b) Surface area created
c) Final Volume
d) Initial feed
Explanation: The Rittingers law states that “The work required in crushing is directly proportional to the new surface area created”.
2. Following Rittingers law, Crushing efficiency is ____
a) Independent of feed material
b) Independent of size of feed and product
c) Independent of energy consumed
d) Independent of area
Explanation: Crushing efficiency is constant and for a given machine and feed material, is independent of size of feed and product.
3. What does the below equation represent?
Explanation: The formula above represents the Rittingers law, where P is the power required, m is the mass and Kf is the constant.
4. Rittingers law is applicable only when _____
a) New particles are created
b) New surface area is created
c) Energy is created
d) Energy is absorbed
Explanation: Rittingers law applies well where new surface area is created and hold good for fine grinding where increase is surface area per unit mass is large.
5. On which of the given, Kick’s law is based?
a) Cumulative analysis
b) Frequency analysis
c) Stress analysis
d) Screen analysis
Explanation: Kick proposed another law, based on the stress analysis of plastic deformation within the elastic limits.
6. According to Kick, the work required for crushing a mass of material is ____
Explanation: The kick’s law states that the work required for crushing a mass of material is constant for the same reduction ratio.
7. The ratio of initial particle size to final particle size is defined as _____
a) Reduction ratio
b) Kick’s ratio
c) Rittingers ratio
d) Bond’s ratio
Explanation: The reduction ratio for a crusher is defined as the ratio of feed opening to the discharge opening i.e. Dsa/Dab.
8. What does the below equation represent?
a) Arrhenius Law
b) Kick’s Law
c) Bond Law
d) Rittingers Law
Explanation: The formula above represents the Kick’s law, where P is the power required, m is the mass and Dsa/Dab is the reduction ratio and Kk is the kick’s constant.
9. Kick’s law holds well for ____
a) Fine crushing
b) Simple crushing
c) Full crushing
d) Coarse crushing
Explanation: Kick’s law holds good for coarse crushing and amount of surface produced is less.
10. The below equation is in the form of____
a) Experimental relation
b) Empirical relation
c) Generalized relation
d) Actual relation
Explanation: The generalized relation is in the form of the above equation that is the form of the differential equation, where the value of ‘n’ varies.
Sanfoundry Global Education & Learning Series – Mechanical Operations.
To practice all areas of Mechanical Operations, here is complete set of 1000+ Multiple Choice Questions and Answers.