The specific gravity of most of the stones lies between:
- A2 and 3Correct
- B3.5 and 4
- C3 and 3.5
- D1 and 2
Solution
Concept
Most building stones have specific gravity between 2.4 and 2.8, so the range is 2 to 3.
Step-by-step solution
1. Recall the specific gravity of common building stones. 2. Granite is about 2.6 to 2.7, sandstone about 2.2 to 2.6, limestone about 2.6, marble about 2.7. 3. All these values fall between 2 and 3. 4. So the answer is (A).
Explanation
Most building stones have specific gravity between about 2.4 and 2.8. A good building stone usually has specific gravity above 2.7. So the general range is 2 to 3.
Why the other options are wrong
(B) 3.5 to 4 is too high for common stones. (C) 3 to 3.5 is higher than most stones. (D) 1 to 2 is too low; that range suits light materials like timber or pumice.
Shortcut
Stone specific gravity is about 2.65, almost the same as soil solids.
Common mistake
Mixing up specific gravity of stone with that of cement (about 3.15).
Correct answer: A) 2 and 3