Which of the following statements is/are CORRECT regarding rotavator blades and their kinematic parameters?
Options:
(A) L-shaped blades are superior in killing weeds and handling trash without wrapping
(B) C-shaped blades are recommended for heavy wet soils and puddling operations
(C) The ratio of blade peripheral speed to tractor forward velocity (velocity ratio $\lambda$) must be greater than $1$ for cutting action
(D) Down-cut rotavators exert a positive forward thrust on the tractor during operation
Answer Key:
A, B, C, D
Step-by-Step Solution & Explanation
1. L-shaped blades cut vegetation cleanly and are less prone to clogging in trashy conditions. (A is correct)
2. C-shaped blades curve smoothly and require less power in wet soils, ideal for wetland puddling. (B is correct)
3. For cycloidal blade motion to loop and cut soil effectively, $\lambda = u / v > 1$. (C is correct)
4. In down-cut rotavators, blades rotate in the same direction as tractor wheels, pushing the tractor forward. (D is correct)
All four statements A, B, C, D are correct.