Question

The ratio of specific weight of a liquid to the specific weight of pure water at a standard temperature is called

• A. Density of liquid
• B. Specific gravity of liquid
• C. Compressibility of liquid
• D. Surface tension of liquid

Hint:

Remember, \[ \boxed{ SG=\frac{\gamma}{\gamma_w} = \frac{\rho}{\rho_w} } \] Specific gravity is always dimensionless.

Answer 1

The Correct Option is B

Concept: Specific gravity is a dimensionless quantity that compares the specific weight (or density) of a liquid with that of pure water at a standard temperature. It is defined as \[ \boxed{ SG=\frac{\gamma}{\gamma_w} } \] where \[ \gamma=\text{Specific weight of the liquid}, \] and \[ \gamma_w=\text{Specific weight of water}. \] Since both quantities have the same units, specific gravity has no unit.

Step 1: Understand the definition. Specific gravity compares the heaviness of a liquid with water. If \[ SG>1, \] the liquid is heavier than water. If \[ SG<1, \] the liquid is lighter than water.

Step 2: Identify the required quantity. The given definition exactly represents \[ \boxed{\text{Specific Gravity}.} \] Therefore, the correct option is \[ \boxed{(B)\;\text{Specific gravity of liquid}.} \]