Question

The pressure at the bottom of a tank of liquid is not proportional to

• A. The density of the liquid
• B. The area of the liquid surface
• C. The height of the liquid
• D. The acceleration due to gravity

Answer 1

Answer: (B)

The pressure depends on acceleration, the height of the liquid and the density of the liquid. Pressure does not depend on the area of the liquid surface.

Force, $F=(hA)\rho g$
$\Rightarrow F=hA\rho g$
Pressure, $P=\frac{F}{A}$
$\Rightarrow P=h\rho g$
As we know, P = P_atm + ρgh
From this equation, pressure is independent of the area of the liquid surface.
Hence, the area of the liquid surface is correct.