Question

A beaker is filled with a liquid of specific gravity S = 1:2 as shown. What will be the pressure difference (in kN/m^2) between the two points A and B, 30 cm below and 10 cm to the right of point A?

(a) 2.5

(b) 3.5

(c) 4.5

(d) 5.5

The question was asked during a job interview.

I would like to ask this question from Pressure Distribution in a Fluid in chapter Pressure and Its Measurement of Fluid Mechanics

Answer 1

The correct choice is (b) 3.5

For explanation: Pressure increases in the vertically downward direction but remains constant in the horizontal direction. Thus,

PB = PA + ρgh

where PB = Pressure at B, PA = Pressure at A, ρ = density of the liquid, g = acceleration due to gravity and h = vertical distance separating the two points.

PB – PA = 1:2 * 10^3 * 9.81 * 0.3 N/m^2 = 3.53 kN/m^2