Glycerine of density $1.25 \times 10^3\,kg\,m ^{-3}$ is flowing through the conical section of pipe. The area of cross-section of the pipe at its ends is $10\,cm ^2$ and $5\,cm ^2$ and pressure drop across its length is $3\,Nm ^{-2}$. The rate of flow of glycerine through the pipe is $x \times 10^{-5} m ^3 s ^{-1}$. The value of $x$ is $..............$.
JEE MAIN 2023, Diffcult
Download our app for free and get startedPlay store
$\Delta P = P _1- P _2=3 N / m ^2 \text { (given) }$

By continuity $eq ^{ n }$

$A _1 v _1= A _2 v _2$

$\therefore \quad v_1=\frac{A_2}{A_1} v_2-(1)$

By Bernoulli's equation.

$P _1+\frac{1}{2} \rho v _1{ }^2= P _2+\frac{1}{2} \rho v _2{ }^2$

$P _1- P _2=\frac{1}{2} \rho\left( v _2^2- v _1^2\right)$

$\Delta P =\frac{1}{2} \rho\left( v _2^2-\frac{ A _2^2}{ A _1^2} v _2^2\right)$

$\Delta P =\frac{1}{2} \rho\left[1-\left(\frac{ A _2}{ A _1}\right)^2\right] v _2^2$

$3=\frac{1}{2} \times 1.25 \times 10^3\left[1-\left(\frac{5}{10}\right)^2\right] v _2^2$

$3=\frac{1}{2} \times 1.25 \times 10^3\left[1-\frac{1}{4}\right] v _2^2$

$3=\frac{1}{2} \times 1.25 \times 10^3 \times \frac{3}{4} v_2^2$

So discharge rate $= A _2 V _2$

$=5 \times 10^{-4} \times 8 \times 10^{-2}$

$=4 \times 10^{-5}\,m ^3 / s$

Correct ans is $x=4$

art

Download our app
and get started for free

Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*

Similar Questions

  • 1
    The velocity of upper layer of water in a river is $36 kmh ^{-1}$. Shearing stress between horizontal layers of water is $10^{-3} Nm ^{-2}$. Depth of the river is $m$. (Co-efficiency of viscosity of water is $10^{-2} \,Pa . s$ )
    View Solution
  • 2
    $Assertion :$ A bubble comes from the bottom of a lake to the top.
    $Reason :$ Its radius increases.
    View Solution
  • 3
    Horizontal tube of non-uniform cross-section has radii of  $0.1\,m$ and  $0.05\,m$ respectively at $M$  and  $N.$  For a stream-line flow of liquid the rate of liquid flow is
    View Solution
  • 4
    Horizontal tube of non-uniform cross-section has radii of  $0.1\,m$ and  $0.05\,m$ respectively at $M$  and  $N.$  For a stream-line flow of liquid the rate of liquid flow is
    View Solution
  • 5
    A barometer kept in a stationary elevator reads $76 cm$. If the elevator starts accelerating up the reading will be
    View Solution
  • 6
    Water from a tap emerges vertically downwards with an initial speed of $1.0\,ms^{-1}.$ The cross-sectional area of the tap is $10^{-4}\,m^2.$ Assume that the pressure is constant throughout the stream of water and that flow is streamlined. The cross-sectional area of the stream, $0.15\,m$ below the tap would be: (take $g = 10\,ms^{-2}$ )
    View Solution
  • 7
    Which of the following is the incorrect graph for a sphere falling in a viscous liquid? (Given at $t = 0$, velocity $v = 0$ and displacement $x = 0$.) 
    View Solution
  • 8
    The three water filled tanks shown have the same volume and height. If small identical holes are punched near this bottom, which one will be the first to get empty.
    View Solution
  • 9
    In Poiseuilli's method of determination of coefficient of viscosity, the physical quantity that requires greater accuracy in measurement is
    View Solution
  • 10
    A vessel containing water is moving with a constant speed towards right along a straight horizontal path. if the vessel is given a constant retardation towards the right along a straight line, which of the above diagram represents the surface of the liquid?
    View Solution