Specific Gravity is defined as the ratio of the mass of a given volume of a substance to the mass of an equal volume of water at 4°C.

Specific Gravity is defined as the ratio of the mass of a given volume of a substance to the mass of an equal volume of water at 4°C.

• A. Relative Humidity
• B. Density
• C. Specific Gravity of a liquid or solid
• D. Buoyancy

Answer: (C)

The main idea being tested is what specific gravity actually measures. Specific gravity is the comparison of how dense a substance is relative to water, using the same volume of each. By defining it as the ratio of the mass of a given volume of the substance to the mass of an equal volume of water at 4°C, you’re describing a dimensionless quantity that tells you how the substance’s density stacks up against water. That’s why the best answer is the term that denotes this ratio for liquids or solids: Specific Gravity of a liquid or solid. It captures the idea of comparing density to water, rather than giving an absolute density value. Since water at 4°C has a density of about 1 g/cm3, the specific gravity essentially mirrors the substance’s density in g/cm3, but as a pure ratio. Understanding this helps: if the SG is greater than 1, the material is denser than water and tends to sink; if it’s less than 1, it’s less dense and tends to float. The other options don’t fit because relative humidity relates to moisture in air, buoyancy is the upward force objects experience in fluids, and density is an absolute property, not the specific ratio to water that SG defines.

The main idea being tested is what specific gravity actually measures. Specific gravity is the comparison of how dense a substance is relative to water, using the same volume of each. By defining it as the ratio of the mass of a given volume of the substance to the mass of an equal volume of water at 4°C, you’re describing a dimensionless quantity that tells you how the substance’s density stacks up against water.

That’s why the best answer is the term that denotes this ratio for liquids or solids: Specific Gravity of a liquid or solid. It captures the idea of comparing density to water, rather than giving an absolute density value. Since water at 4°C has a density of about 1 g/cm3, the specific gravity essentially mirrors the substance’s density in g/cm3, but as a pure ratio.

Understanding this helps: if the SG is greater than 1, the material is denser than water and tends to sink; if it’s less than 1, it’s less dense and tends to float. The other options don’t fit because relative humidity relates to moisture in air, buoyancy is the upward force objects experience in fluids, and density is an absolute property, not the specific ratio to water that SG defines.