Question

In the figure below is shown the flow of liquid through a horizontal pipe. Three tubes A, B and C are connected to the pipe. The radii of the tubes, A, B and C at the junction are respectively 2 cm, 1 cm and 2 cm. It can be said that the :-

• A. height of the liquid in the tube A is maximum
• B. height of the liquid in the tube A and B is the same
• C. height of the liquid in all the three tubes is the same
• D. height of the liquid in the tube A and C is the same

Answer 1

The correct option is D height of the liquid in the tube A and C is the same

It is given that, the radii of the tubes A and C are equal, which means that the speed of the liquid flowing through them would also be equal (this can be said from the application of equation of continuity)

Now, using the Bernoulli's theorem, for points lying in 1 horizontal plane, the pressure at the 2 points will be the same if they are at the same fluid velocity.

Therefore, the liquid levels in the tubes A and C will be the same.