Arrange the following building materials in the increasing order of density of materials: Granite, Steel, River sand, Water
Correct Answer: D. Water, River sand, Granite, Steel
📚 Detailed Explanation: Density Order of Building Materials
Density is the mass per unit volume of a material (kg/m³). To answer this question, you simply need to recall the approximate bulk or solid densities of these four common building materials and rank them from lowest to highest.
Why D is correct: Ranking the four materials by density: Water = 1000 kg/m³ (lightest of the four), River sand (loose bulk density) ≈ 1600–1800 kg/m³, Granite (solid) ≈ 2640–2800 kg/m³, Steel ≈ 7850 kg/m³ (heaviest). So the correct increasing order is Water < River sand < Granite < Steel. Options A and C are wrong because they misplace Steel or Granite.
Approximate Densities of Common Building Materials
| Material | Density (kg/m³) | Notes |
|---|---|---|
| Water | 1000 | Reference density at 4°C |
| River sand (bulk) | 1600–1750 | Loose bulk density including voids |
| Granite (solid) | 2640–2800 | Specific gravity ≈ 2.65–2.80 |
| Structural steel | 7850 | Mild steel / Fe415 |
Key Concepts for Students
- Specific gravity of aggregate is relative to water: granite SG ≈ 2.65, meaning it is 2.65 times denser than water.
- Bulk density includes inter-particle voids; solid (particle) density does not. Sand’s bulk density (≈1700) is much less than granite’s solid density (≈2700) for the same rock type.
- Steel ≈ 7.85 t/m³ — roughly 3× denser than granite and 7.85× denser than water. Always the heaviest in such comparisons.