In a mouldboard plough, the clearance provided under the cutting edge of the share point when the plough rests flat on a level surface is termed as:
Options:
(A) Horizontal suction
(B) Vertical suction
(C) Throat clearance
(D) Lead angle
Answer Key:
B
Step-by-Step Solution & Explanation
```
Plough Suction Schematic:
Level Floor -----------------------------
\ /
\__Vertical Suction_____/
(Gap under share)
```
- **Vertical suction (vertical clearance):** The small gap (typically $3\text{--}5\text{ mm}$) between the share point and the level ground surface when resting on the share wing and landside heel. It enables the plough to penetrate to the desired operating depth.
- **Horizontal suction:** The lateral clearance towards the unploughed land that maintains uniform cutting width.