Question

Consider the following statements about size reduction of solids:
A. Energy requirement increases with hardness
B. Rittinger’s law applies to fine grinding
C. Kick’s law applies to coarse crushing
D. Size reduction always improves food quality
E. Hammer mills operate mainly by impact
Choose the correct answer from the options given below:

• A. B, C, D, E only
• B. B, C, E only
• C. A, B, C, E only
• D. C, D, E only

Hint:

Kick → coarse, Rittinger → fine grinding.

Answer 1

The Correct Option is C

Concept: Size reduction involves breaking solids into smaller particles using mechanical forces and follows certain empirical laws.

Step 1: Evaluating Statement A.
Harder materials:
• Require more energy for size reduction Correct.

Step 2: Evaluating Statement B.
Rittinger’s law:
• Applicable to fine grinding
• Based on surface area increase Correct.

Step 3: Evaluating Statement C.
Kick’s law:
• Applicable to coarse crushing Correct.

Step 4: Evaluating Statement D.
Size reduction:
• May degrade quality (oxidation, heat)
• Not always beneficial Incorrect.

Step 5: Evaluating Statement E.
Hammer mill:
• Works primarily by impact force Correct.

Step 6: Final selection. \[ A, B, C, E \] Final Conclusion:
Option (3) is correct.