Question

If the pressure at a point is 1m of water, what will be it’s value in terms of m of oil? (Take, the specific gravity of oil to be 0.8)

(a) 0.8

(b) 1

(c) 1.25

(d) 2.5

I had been asked this question in homework.

Question is taken from Pressure Distribution in a Fluid in chapter Pressure and Its Measurement of Fluid Mechanics

Answer 1

Right answer is (c) 1.25

The explanation: Pressure at a point P is equal to ρgh, where ρ is the density and h is the height of the liquid column. Therefore, ρwater * 1 * g = ρoil * h * g, where h is the pressure in terms of m of oil.

Thus, h = ρwater / ρoil = 1/0.8 = 1.25.