Download App

STD 11 - 9.1. fluid mechanics — NEET STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceNEETSTD 11 - 9.1. fluid mechanics4 Marks
Question
A space $2.5\ cm$ wide between two large plane surfaces is filled with oil. Force required to drag very thin plate of area $0.5\ m^2$ just midway the surfaces at a speed of $0.5\ m/sec$ is $1\ N$ The coefficient of viscosity in $kg-s/m^2$ is :
✓

Answer

Velocity gradient $=\frac{0.5}{\frac{2.5}{2} \times 10^{-2}}$

as force on the plate due to viscosity is from upper as well as lower portion of the oil, equal from each part,

Then, $\mathrm{F}=2 \eta \mathrm{A} \frac{\mathrm{dv}}{\mathrm{dz}}=2 \times \eta \times(0.5) \frac{0.5}{1.25 \times 10^{-2}}$

$\Rightarrow \eta=2.5 \times 10^{-2} \mathrm{kg}-\mathrm{sec} / \mathrm{m}^{2}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

NEET STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

If energy $(E),$ velocity $(V)$ and time $(T)$ are chosen as the fundamental quantities, the dimensional formula of surface tension will be
→
The earth (mass= $6 \times 10^{24}$ kg ) revolves around the sun with an angular velocity of $2 \times 10^{-7}$ radian/sec in a circular orbit of radius $1.5 \times 10^8 km$. The force exerted by the sun, on the earth is:
→
A monatomic gas at pressure $P_1$ and volume $V_1$ is compressed adiabatically to ${\frac{1}{8}}^{th}$ of its original volume. What is the final pressure of the gas is ........ $P_1$?
→
In $N-$type semiconductors, majority charge carriers are
→
Three blocks $A$, $B$ and $C$ are pulled on a horizontal smooth surface by a force of $80 \mathrm{~N}$ as shown in figure

The tensions $T_1$ and $T_2$ in the string are respectively

→
Which of the following Boolean expression is not correct
→
Two magnetic dipoles $X$ and $Y$ are placed at a separation $d$, with their axes perpendicular to each other. The dipole moment of $Y$ is twice that of $X$. A particle of charge $q$ is passing through their mid-point $P$, at angle $\theta  = 45^o$ with the horizontal line as shown in the figure. What would be the magnitude of force on the particle at that instant ? ($d$ is much larger than the dimensions of the dipole)
→
Radiation coming from transition $n = 2$ to $n = 1$ of hydrogen atoms fall of $He^+$ ions in $n = 1$ and $n = 2$ states. The possible. Transition of helium ions as they absorb energy from the radiation is
→
The temperature at which the vapour pressure of a liquid becomes equals to the external (atmospheric) pressure is its
→
A car of mass $1000\,kg$ is moving at a speed of $30\,m/s.$ Brakes are applied to bring the car to rest. If the net retarding force is $5000\,N,$ the car comes to stop after travelling $d\,m$ in $t\,s.$ Then
→