Question

A liquid flows through a horizontal tube. The velocities of the liquid in the two sections, which have areas of cross-section $A_1$ and $A_2$ are $v_1$ and $v_2$ respectively. The difference in the levels of the liquid in the two vertical tubes is $h$.

A) The volume of the liquid flowing through the tube in unit time is $A_1{v}_1$

B) $v_2-v_1$ = $\sqrt{2gh}$

C) $v_2^2-v_1^2$ = 2gh

D) The energy per unit mass of the liquid is the same in both section of the tube.

• A. A, B are correct
• B. C, D are correct
• C. A, C and D are correct
• D. Only C is correct

Answer 1

The correct option is C

A, C and D are correct

$\frac{p_1}{\rho }+\frac{v_1^2}{2}$ = $\frac{p_2}{\rho }+\frac{v_2^2}{2}$ ($\because$ Point 1 and Ponit 2 are at same level)

But $p_1-p_2$ = ρgh = $\frac{\rho }{2}$ ( $v_2^2-v_1^2$ )