Question

The rate of flow of liquid through a capillary tube in an experiment to determine the viscosity of liquid, increases -

• A. when the pressure of the tube is increased
• B. when the length of the tube is increased
• C. when the radius of the tube is increased
• D. none of the above

Answer 1

The correct option is A when the pressure of the tube is increased

Using Bernoulli's equation,
for points lying in the same horizontal plane,
The velocity of a fluid is governed by the pressure difference applied across the tube.
$\delta P+0.5\rho \delta v^2=0$
Therefore, as you increase the pressure gradient applied, the rate of flow of the fluid will increase.