Question

The diagram shows a venturimeter through which water is flowing. The speed of water $X$ is $2{\text{cms}}^{-1}$. The speed of water at $Y$ $(takingg=10{\text{ms}}^{-2})$ is

• A. $23{\text{cms}}^{-1}$
• B. $32{\text{cms}}^{-1}$
• C. $101{\text{cms}}^{-1}$
• D. $1024{\text{cms}}^{-1}$

Answer 1

The correct option is B $32{\text{cms}}^{-1}$

$p_x-p_y=\frac{\rho }{2}(v_y^2-v_x^2)\Rightarrow \Delta h\rho g=\frac{\rho }{2}(v_y^2-v_x^2)\Rightarrow \Delta hg=\frac{1}{2}(v_y^2-v_x^2)\Rightarrow 0.51\times 1000=\frac{1}{2}(v_y^2-2^2)\Rightarrow 1020=v_y^2-4\Rightarrow 1024=v_y^2\Rightarrow v_y=32cm/s$