Question

The volume of a liquid flowing per second out of an orifice at the bottom of a tank does not depend upon

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

Answer 1

Answer: (C)

the density of the liquid

Volume of a liquid flowing per second is equal to the product of area and velocity of liquid i.e. $Q=Av$
According to Torricelli's Theorem velocity of efflux $v$ i.e. the velocity
with which the liquid flows out of a hole is equal to $\sqrt{2gh}$ where $h$ is the depth of the hole below the liquid surface. So we have
$Q=A\sqrt{2gh}$
hence Volume of a liquid flowing per second depends upon

• the height of the liquid above the orifice
• the acceleration due to gravity
• the area of the orifice

and it is independent of the density of the liquid.