Question

A piece of metal weighs $155g$ in air, $150g$ in water and $130g$ in liquid. The relative density of the metal and that of liquid are respectively

• A. 5,5
• B. 30,5
• C. 31,5
• D. 10,15

Answer 1

Answer: (C)

Relative density of solid =
$\frac{\text{ weight in air }}{\text{ weight in air }-\text{ weight in water }}$
$\therefore \text{ Relative density of solid }=\frac{155}{155-150}$
$R.D=\frac{155}{5}=31$
Relative density of liquid =
$\frac{\text{weight in air - weight in liquid}}{\text{ weight in air - weight in water}}$
$=\frac{155-130}{155-150}=\frac{25}{5}=5$