Question

A closed U-tube manometer has a gas on one end with pressure 10 Pa and other end has vacuum, what is the approximate density of the liquid if the height difference of the liquid is 10 cm?

(a) 1 Kg/m^3

(b) 10 Kg/m^3

(c) 100 Kg/m^3

(d) 1000 Kg/m^3

The question was asked in an online quiz.

Asked question is from Differential Pressure Measurements topic in chapter Temperature and Pressure of Basic Chemical Engineering

Answer 1

Right option is (b) 10 Kg/m^3

To explain I would say: Pressure of gas = Pressure due to height difference of liquid = d*g*h, => 10 = d*10*0.1, => d = 10 Kg/m^3.