Building Stones MCQ with answer and solution

Concept

Good building stones are heavy and dense. Stones with very low specific gravity are porous and weak.

Step-by-step solution

1. The specific gravity of most building stones lies between about 2.3 and 2.8. 2. A higher specific gravity means a denser, stronger and more durable stone. 3. Standard Indian textbooks say stones with specific gravity less than 2.4 are unsuitable for buildings. 4. So the answer is 2.4.

Explanation

Specific gravity shows how dense a stone is. Stones with specific gravity below 2.4 are light, porous and weak, so they are not suitable for building work. Good building stones usually have specific gravity above 2.7.

Why the other options are wrong

A (3.6) and D (3.2): These are too high. Most good stones are below these values. C (2.8): This is the range of good, heavy stones, not the lower limit for unsuitable stones.

Shortcut

Less than 2.4 = unsuitable. More than 2.7 = good stone.

Common mistake

Confusing the lower limit (2.4) with the value expected for good stones (about 2.7 to 2.8).