The grain size (mm) of medium grained sand lies between:
Try it first: pick an option, then read the explanation.
Detailed Explanation
Sand itself is further subdivided by particle size into coarse, medium, and fine categories — a finer-grained breakdown within the broader sand classification already introduced in Q2.
| Sand Sub-Category | Size Range (mm) |
|---|---|
| Coarse Sand | 2.0 to 4.75 |
| Medium Sand | 0.425 to 2.0 |
| Fine Sand | 0.075 to 0.425 |
Why "2.0 to 0.425" Is Correct
Medium sand is defined as particles ranging from 0.425 mm to 2.0 mm in size — sitting between coarse sand (2.0-4.75 mm) and fine sand (0.075-0.425 mm).
Why the Other Options Are Wrong
- 0.425 to 0.075: this is the fine sand range, not medium sand — one tier too fine.
- 4.75 to 2.0: this is the coarse sand range, not medium sand — one tier too coarse.
- 20 to 4.75: far too coarse for sand at all — this range sits within gravel-sized material, well above sand's upper bound of 4.75 mm.
Key Point
Coarse (2.0-4.75), Medium (0.425-2.0), Fine (0.075-0.425) — memorize this three-tier sand sub-classification as a single ordered sequence rather than three isolated facts.
Key Concepts for Students
- This sub-classification refines the broader sand category already introduced in Q2 (0.075-4.75 mm overall) into three named bands.
- See Q34 for this same sub-classification applied to identify a specific 0.2 mm particle as "fine sand."
- 0.425 mm and 2.0 mm are the two internal boundaries within the sand range — worth keeping distinct from sand's own outer boundaries (0.075 mm and 4.75 mm).
- This same fine/medium/coarse sub-tiering logic doesn't stop at sand — silt and gravel are sometimes similarly subdivided in more detailed classification schemes, though this topic's questions focus specifically on the sand sub-tiers.
Going Deeper: Sand's Internal Sub-Classification, in Context
Sand's 0.075-4.75 mm range (see Q2) is wide enough that engineers frequently need to distinguish coarser from finer sand within that range — for grading analysis, concrete mix design (see Q8, Q10's fine-aggregate zones), and general soil description.
The complete IS particle-size classification, from finest (clay) to coarsest (boulder). Fine-grained soil = silt + clay (<0.075mm); coarse-grained soil = sand + gravel (>0.075mm).
| Category | Size Range |
|---|---|
| Fine Sand | 0.075 mm – 0.425 mm |
| Medium Sand | 0.425 mm – 2.0 mm |
| Coarse Sand | 2.0 mm – 4.75 mm |
This sub-classification connects directly to the fine-aggregate grading zones (IS 383, see Q8 and Q10) used in concrete work: those zones essentially describe different blends of fine, medium, and coarse sand, with Zone I skewed coarser and Zone IV skewed finer within this same 0.075-4.75 mm overall sand range.