Mechanical properties of fluids practice · Medium

Statement A: Surface tension has same units as force gradient
Statement B: Surface tension is the force gradient along the surface of liquid

The pressure at the bottom of a tank containing a liquid does not depend on

Water flows through a horizontal pipe of radius '$r$' at a speed '$V$'. If the radius of the pipe is doubled, then the speed of flow of water under similar conditions is

Water is flowing with velocity $4 \mathrm{~m} / \mathrm{s}$ in a cylinder of diameter $8 \mathrm{~cm}$, it is connected to a pipe with it end tip of diameter $2 \mathrm{~cm}$, calculate the velocity of water at this free end.

A log of wood floats in water with $\frac{1}{4}$ of its volume above the surface. What is the density of wood ?

A block of ice of total area $A$ and thickness $0.5 \mathrm{~m}$ is floating in water. In order to just support a man of mass $100 \mathrm{~kg}$, the area $A$ should be (the specific gravity of ice is 0.9)

Let $W$ be the work done, when a bubble of volume $V$ is formed from a given solution. How much work is required to be done to form a bubble of volume $2 {~V}$ ?

A solid sphere falls with a terminal velocity of $10 \mathrm{~cm} / \mathrm{s}$ in the earth's gravitational field. If it is released from rest in a gravity free space then terminal velocity will be

Air is streaming past a horizontal air plane wing such that its speed is $120\mathrm{m}{\mathrm{s}^{ - 1}}$ over the upper surface and $90\mathrm{m}{\mathrm{s}^{ - 1}}$ at the lower surface. If the density of air is $1.3\mathrm{kg}{\mathrm{m}^{ - 3}}$, what will be the gross life on the wing? If the wing is $10\mathrm{m}$ long and has an average width of 2 m,

The ratio of radii of two bubbles is $2: 1$ What is the ratio of excess pressures inside them?

Two spherical soap bubbles of radii $a$ and $b$ in vacuum coalesce under isothermal conditions. The resulting bubble has a radius given by

When the temperature is increased, the angle of contact of a liquid

Assertion: The size of the needle of a syringe controls flow rate better than the thumb pressure exerted by a doctor while administering an injection.
Reason: Flow rate is independent of pressure exerted by the thumb of the doctor.

Given below are two statements:

Statement I: Pressure in a reservoir of water is same at all points at the same level of water.

Statement II: The pressure applied to enclosed water is transmitted in all directions equally.

In the light of the above statements, choose the correct answer from the options given below:

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: When you squeeze one end of a tube to get toothpaste out from the other end, Pascal's principle is observed.

Reason R: A change in the pressure applied to an enclosed incompressible fluid is transmitted undiminished to every portion of the fluid and to the walls of its container.

In the light of the above statements, choose the most appropriate answer from the options given below.

How much pressure will a man of weight $80 \mathrm{~kgf}$ exert on the ground when he is lying on the ground. Given that the area of the body of the man is $0.6 \mathrm{~m}^2$ and that of a foot is $80 \mathrm{~cm}^2$.

An atmosphere,

A water drop of diameter 2 cm is broken into 64 equal droplets. The surface tension of water is $0.075\,\,N/m.$ In this process the gain in surface energy will be

The depth of water at which air bubble of radius 0.4 mm remains in equilibrium is $\left( {{T_{\mathrm{water}}} = 72 \times {{10}^{ - 3}}\,\,N/m} \right)$

The work done in blowing a spherical soap bubble of diameter 2 cm will be (T = 0.02 N/m)

Assertion: Water drop stick to glass surface.
Reason: Water have properties of surface tension.

Assertion:- Machine parts are jammed in winter.
Reason:-The viscosity of lubricant used in machine part decrease at low temperature.

Assertion: A surface tension experiment with a capillary tube is done on an artificial satellite then the rise of liquid in the capillary is upto full length of the tube.
Reason: The value of $g_{\text {effective}}$ is zero on an artificial satellite.

Water is flowing in a pipe of radius $1 {~cm}$ with an average velocity $20 {~cm} / {s}$. If coefficient of viscosity of water is $10^{-3} {~kg} {~m}^{-1} {~s}^{-1}$ and density is $10^3 {~kg} / {m}^3$, then the nature of flow is

What would be the pressure inside a small air bubble of $1.0\,mm$ radius situated just below the surface of water? $\left[ {T = 72 \times {{10}^{ - 3}}\,N/m;{\rho _0} = 1.013 \times {{10}^5}\frac{N}{{{m^2}}}} \right]$

A piece of wood is floating in water kept in bottle. The bottle is connected to an air pump. Neglect the compressibility of water. When more air is pushed into the bottle from the pump, the piece of wood will float with

While measuring surface tension of water using capillary
rise method, height of the lower meniscus from free
surface of water is 3 cm while inner radius of capillary tube is found to be 0.5 cm. Then, compute tension of
water using this data (take, contact angle between glass
and water as $0$ and $g = 9.81 \text{m/s}^2)$

A horizontal tube has different cross-sectional areas at points $A$ and $B$. The diameter of $A$ is $4 \mathrm{~cm}$ and that of $B$ is $2 \mathrm{~cm}$. Two manometer limbs are attached at $A$ and $B$. When a liquid of density $8.0 \mathrm{~g} \mathrm{~cm}^{-3}$ flows through the tube, the pressure difference between the limbs of the manometer is $8 \mathrm{~cm}$. Calculate the rate of flow of the liquid in the tube.

Calculate the diameter of a capillary tube in which mercury is depressed by $1.21 \mathrm{~cm}$. Given surface tension for mercury is $540 \times 10^{-3} \mathrm{~Nm}^{-1}$, the angle of contact with glass is $140^{\circ}$ and density of mercury is $13.6 \times 10^3 \mathrm{~kg} \mathrm{~m}^{-3}$.

Height $h$ of water raised in a capillary tube of radius $r$ depends on $r$ as