Question Bank • QB_PARAMETRIC_FM_MB_025MCQ • 1 Mark
Section 2: Farm Machinery
Primary Tillage: Mouldboard Ploughs & Forces
Subtopic: Specific draft calculation
Question Statement:
A single-bottom mouldboard plough has a width of cut of $30\text{ cm}$ and operates at a depth of $13\text{ cm}$. If the specific soil draft is $0.4\text{ N/cm}^2$, the total draft required by the plough bottom is: (Variation QB_PARAMETRIC_FM_MB_025)
Options:
(A) $156.0\text{ N}$
(B) $187.2\text{ N}$
(C) $124.8\text{ N}$
(D) $234.0\text{ N}$
Answer Key:
A
Step-by-Step Solution & Explanation
The total draft $D$ is the product of cross-sectional area of the furrow slice and the unit draft (specific draft):
$\text{Cross-sectional Area } A = w \times d = 30\text{ cm} \times 13\text{ cm} = 390\text{ cm}^2$
$\text{Total Draft } D = A \times \text{Specific Draft} = 390\text{ cm}^2 \times 0.4\text{ N/cm}^2 = 156.0\text{ N}$
Hence, the correct draft is $156.0\text{ N}$.