In a modern rubber-roll paddy dehusker, dehusking is accomplished primarily by shearing action created because:
Options:
(A) The two rubber rolls rotate inward in opposite directions at different peripheral surface speeds (speed ratio $\approx 1:1.2$ to $1:1.25$)
(B) The two rolls rotate at identical rotational speeds in the same direction
(C) Paddy kernels are pulverized against stationary steel impact pins
(D) Centrifugal forces throw grains against a carborundum stone lining
Answer Key:
A
Step-by-Step Solution & Explanation
In a rubber roll sheller, two resilient rubber-coated rolls rotate toward each other at differential speeds (fast roll typically $1000-1100\text{ rpm}$, slow roll $800-900\text{ rpm}$, speed ratio $1:1.20-1.25$). The peripheral speed difference exerts a strong, gentle shearing force that peels off the loose husk with minimal kernel breakage.